There is something else we should note regarding Zara's weakness.
Our original plan was to give Zara Theology so that he will build the AP. Dhoom already said that AP in the hands of the Buddhists is a problem.
Now, Zara is very weak and I don't think he will build the AP even if we give Theology to him. We must consider alternatives.
Obviously, we can make contact with another Civ (like Zara did). Maybe we should seek it quickly and spread conf. to it before it becomes Buddhist.
Very good point, Havr! We can't really rely on Zara to build the Apostolic Palace.
So, can or should it be built in Riverdale? It's a neat idea to do so. However, should we really hand over the keys to both vaults to Zara in the end? "Dear Zara, here are both the Apostolic Palace and The United Nations as part of the deal giving you Riverdale. Please be nice to us and let us win the game."
The idea of letting an AI build the Apostolic Palace for us was because of the high Hammer cost. The downside to letting an AI build it is that said AI will spread the religion that it is built in throughout all of its Cities.
If that religion is Buddhism, then our plan is for most of the world to have that religion, so lots of Apostolic Palace voting will occur with a bunch of AIs that like each other, perhaps giving away the game.
If that religion isn't Buddhism, then that AI will likely not switch out of said religion, so we'll have essentially created a "Holy City" for that one AI.
So, it looks like we're on the hook for building the Apostolic Palace ourselves.
Delhi is going to be busy with The Pyramids and probably soon after, The Hanging Gardens. However, we could dedicate Delhi to building only buildings and Wonders, if we farm off the Settler-building to somewhere else, leaving Delhi to go after the Apostolic Palace shortly thereafter.
Delhi would be a decent place, since it has several Mines and the population to use them. However, building The Apostolic Palace there could tie up Delhi for a long, long time.
Perhaps Stone City would be the best place to put it, if we can manage to settle the City to include the Marble and Cow for the required additional production. I believe that we'll need a Confucian Missionary there after Christianity is founded, as, if I recall correctly, you have to have your current State Religion in a City in order to build The Apostolic Palace.
We'd then switch to Christianity for 5 turns in order to complete the Apostolic Palace, because the less AIs that have its religion, the better. Either that, or we'll spread Judaism and/or Hinduism from one or both of our other two Holy Cities, in addition to having already spread Confucianism in Stone City, and then have the choice of which Religion to use for the Apostolic Palace around the time that it will be complete.
The ideal religion to use would be one that isn't well-spread, so we can check the F7 screen at the time of completing the Apostolic Palace to see which religion has the least influence in the world and pick that religion.
Pros of building the Apostolic Palace in Stone City:
1. We won't have to give away the Apostolic Palace when we gift The United Nations
2. We had nothing slated to build in Stone City anyway
3. The Wonder isn't great for Cultural-to-Hammers output (it's a terrible Wonder for that, actually), so the loss of potential culture in Riverdale is actually a gain (Riverdale could make a lot more culture building by building other buildings with the same amount of Hammers)
4. "Slow and steady wins the race": this City is a slow-grower, so it's not ideal for building Settlers and Workers, but is ideal for building a big-Hammer-project where it can slowly grow in population-size over time
5. It leaves Delhi free to build more important things, like the odd Settler, Monastaries, and more Wonders
Cons of building the Apostolic Palace in Stone City:
1. Stone City would HAVE to be settled to include the Cow and Marble, otherwise we won't have enough production in that City
2. We won't get an AI's Hammers used for building the Wonder for us
3. We'll have to delay building a lot of that Religion's buildings until we get Buddhism for ourselves and spread it manually. Why? Well, every time that you build a Temple or a Monastary of a religion, that religion has a greater chance than on a normal turn of spreading to a religionless City somewhere in the world. So if we start spamming Temples and Missionaries immediate before or after completing the Apostolic Palace, we might soon see a bunch of AIs with that religion, too, which would create us a lot of headaches. So, basically, we'll build the Apostolic Palace for denial-purposes, but will not really get to use its Hammer benefits for a long time, until the world other than Zara, including us, is able to switch to Buddhism.
So, I'm going to suggest that we keep Theology (and Code of Laws--so that no one uses Code of Laws to steal Philosophy from us) to ourselves. We'll aim to put the Apostolic Palace in Stone City. The sooner that we get a Confucian Missionary to spread Confucianism in Stone City, the sooner that we can get started on the Wonder, so that we will have a big head-start over an AI that self-techs Christianity.