If you think there are other simular categories that could be grouped together, then consider having higher level categories.
See this discussion for example
Or the Global Cemeteries Project as a model of what could be done for Churches.
Organizing by the Church is fine. There exists a Quakers Meethouses Category as well.
If you are going to have several of these, it is possible to add them under cities as well. The Global Cemeteries project is once again a great model for how this could work.