I'll preface my comments by saying I do attend Alanon and get benefit from it - that said I do think it has it's faults. For me I just take what I want and leave the rest...sometimes that's hard though.
Like Mike I as an agnostic do think it IS a Christian program - that said if you live in a big city like I do you can go to various meetings until you find one that does not focus on the religious aspect. My group only does the serenity prayer and is not religion focused - though there have been speakers who have gone up there and said "if you continue this program you will come to understand a GOD" - then they said it is a spiritual program. My inner child was screaming during that meeting...I had to keep saying "take what you want and leave the rest". I come from a childhood where religion was used as a tool to control (ie "if you don't do what I want and say you will go to hell" was my mother's favorite) so I'm extra sensitive to it.
Also...and this is just me but I have issues with some of the literature/ideas that seems outdated to me and doesn't empower women. There is a success story in one of the books that talks about a woman going back to her abusive A husband who is now an RA and "only throws things" so isn't THAT abusive anymore....I know take what I want and leave the rest but sometimes I have a moral issue being in a program that does that because it goes against *my* core beliefs to condone in any way for women not to empower themselves (and instead to do what it takes for their man/relationship - especially with abuse). Also some speakers talking about sticking by their man at all costs have made me cringe (my inner child wanted to walk out that day but I kept telling myself "take what you want and leave the rest").
All that said - No I do not think Alanon is a cult - LOLOLOL!!!! hahahahah. That's what take what you want and leave the rest is all about. My STBXAH said the same thing once LMAO when he was trying to manipulate me.
Also I do STRONGLY suggest Alanon despite what I said above - I think it's about finding the right meeting and doing the old take what you want and leave the rest. I've gotten benefit from being in a positive room, from the support and from the slogans. I even adjusted a few of the steps to fit my agnostic beliefs and worked them and it did help.