Very enjoyable
I have some questions and coments though.
Firstly, what is meant by 60% spread of the religon? Maybe I am not sure of how religon is spread in vanilla but if a city has it does it simply not have it... and therefore if you get Buddism when you have one city (which is usally the case IF you get it) you should get a Holy Founder for it.
Well in my first play I founded both Buddism and Confusism with only my capital. Never got the founder. THen when I had about 5 cities I spread my state religon (buddism) to them all... Still no founder. In addition in that game I founded 5 of the 7 religons.... This tells me that the AI is picking up on some bug or something... namely that you can not get a founder if you actually 'founded' the religon... Atleast so it seemed.
I played a couple games (about 100 turns or so) and this was always the case when I founded a religon. So I changed Civs (from India to Persia) and played more militaristic. In that game Confusism eventually founded its way to my lands and around the 1000AD I got a founder.
Not sure if you hardcoded something so you could not get a founder if the religon initialized to more than 60% (thus you have 1 city and it is founded in it) or what, but it was frustrating.
My only other comment is on when you get the Holy Founder. All of the wonders should display their effects and their requirements. Currently only the ones you can build show these facts. Thus you have no knowledge (unless you go into Civ pedia) of the other wonders effects or what needs to be done to build that instead... Not a biggy but would just be better to display it regardless I think.
I think I had some other stuff but I am gonna eat dinner now.

I have some questions and coments though.
Firstly, what is meant by 60% spread of the religon? Maybe I am not sure of how religon is spread in vanilla but if a city has it does it simply not have it... and therefore if you get Buddism when you have one city (which is usally the case IF you get it) you should get a Holy Founder for it.
Well in my first play I founded both Buddism and Confusism with only my capital. Never got the founder. THen when I had about 5 cities I spread my state religon (buddism) to them all... Still no founder. In addition in that game I founded 5 of the 7 religons.... This tells me that the AI is picking up on some bug or something... namely that you can not get a founder if you actually 'founded' the religon... Atleast so it seemed.
I played a couple games (about 100 turns or so) and this was always the case when I founded a religon. So I changed Civs (from India to Persia) and played more militaristic. In that game Confusism eventually founded its way to my lands and around the 1000AD I got a founder.
Not sure if you hardcoded something so you could not get a founder if the religon initialized to more than 60% (thus you have 1 city and it is founded in it) or what, but it was frustrating.
My only other comment is on when you get the Holy Founder. All of the wonders should display their effects and their requirements. Currently only the ones you can build show these facts. Thus you have no knowledge (unless you go into Civ pedia) of the other wonders effects or what needs to be done to build that instead... Not a biggy but would just be better to display it regardless I think.
I think I had some other stuff but I am gonna eat dinner now.