Being in a church doesn't make you religious any more than being in a garage makes you a car.
My meetings are held in a church building but are not religious in nature. People talk about a higher power - but everyone's free to define that as they see fit. My atheist friend refers to The Universe as her higher power - it's more about not trying to control everything yourself and trusting that it will work out than it is about any particular kind or religious faith.
So I wouldn't rule out Alanon simply based on that.
