Watchtower isn't a religion it is a publishing house or media company. Even they say they are not a religion.
As far as I understand, in USA, Christianity is not a religion. It is a way of life. I can't quite remember how it is defined but I think it is that fact that Jesus is the truth. Therefore truth cannot be a religion. And personally I don't think of Jesus as being 'religious'. I used to ask people on the min if they thought Jesus was religious. Generally people answered 'no'. In fact I don't remember anyone saying 'yes.'
Key point about WT is that the published material is a double-cross, full of misleading info. Given that, I don't see how the corporation can be described as Christian. But this is true of other corporations that claim to be Christian.