Adopting the religions from other civs

I have some questions about how getting a religion developed by an AI civ works. In some games I tend not to form a religion at all, and let the AI spread a religion to my cities, and/or conquer an AI with a fully developed religion (all Pantheon, Founder, Follower, Enhancer & Reformation beliefs adopted). But I have noticed that I do not benefit from all the adopted beliefs. For example in one game the AI formed a religion that had the "To the Glory of God" reformation belief, and I conquered all of the cities (so I was in possession of the holy city) and also had that religion in the majority of my cities. But I was unable to buy any great person even though I was in the modern era. I could only buy the great person types corresponding to my completed policy tracks. In the same game on other cities I had a religion which had the "Jesuit Education" reformation belief and I was able to buy the science buildings with faith.
I understand that I do not get the benefit from the Founder beliefs, but what about the reformation beliefs? It seems that some work and some don't. Is this a bug or is this the indented purpose? Are there other beliefs that do not work when you adopt the religion of another civilization? I mention that the game was BNW without any mods.

Whether you get the benefit of another religion's reformation beliefs depends on the belief. As you note, you can benefit from Jesuit Education, but not To the Glory of God. See http://forums.civfanatics.com/showthread.php?t=521454 and related articles.

Thank you for the quick response. That is a very interesting article.