Borobudur + Great Mosque of Djenne = Not working

So I built both of these Wonders in the same city and when I use my missionaries with Interfaith Dialogue, I don't get a science boost? Is this a known bug?

Are you sure you are "speading this religion to cities of other religions?". Just a guess. Interfaith dialogue is a little weird.

I'm guessing that is the problem, I was spreading it to cities without a religion. Time for a change of tactics, I guess.

Like Olodune wrote, ID is very counter-intuitive. I have tried a few games to get something noticeable from it, but I was not impressed. The timing is never very good, since you don't actually want to convert cities. There only a few good target early. Later game, the science you get isn't very significant. It was a lot of work for not much effect in my experience.

Interfaith dialog is amazing if you plan to only have your capital following that religion AND you're making lots of faith.

Buy missionaries in you capital, try to convert your own cities (purposefully choose cities that WONT convert to your religion, and watch the science roll in. Interfaith dialog gives you science equal to 2 turns of whatever you're making now. Meaning that every missionary you make will shave 4 turns off the cost of whatever you're researching. That can add up to -20 turns spent on researching quite easily! A huge advantage!

On the other hand, missionaries are very expensive later on. And, in a kind of tragic irony, researching really quickly will increase the cost of your missionaries.

I always get interfaith dialog when I'm 100% sure I won't be able to spread my religion EX: Diety.

Interfaith Dialogue gives 10 Science for every follower of the other religion(s) in the city.

Ten.

In the medieval era, that is hundreds of faith for a fraction of a turn of science. It is unimaginable this could ever be worth it, when that faith can become a GS in the endgame.

I actually went back to a save right before I founded a religion and replayed the game. I chose Tithe instead which is what I always chose. When I didn't chose it, I was barely making any gold at a key time in the game. I'm addicted to Tithe. I took IF to try something different and it didn't work.

Tithe is terribly weak. Yet is the best founder belief available! It is what I pick almost every time as well.