When my guy and I talk about having a kid, we also look at things like daycare. There’s a local Christian oriented, church-affiliated daycare right on the way to work. I would consider leaving a baby there, but once they are old enough to start asking questions about life, I would feel uncomfortable doing so. This is not to say that I would shelter my kid from Christianity, not by a long shot. They’ll know about as many religions as they care to ask about! But I want to present them as areas of study or options to consider, without one being drummed in as The Only True Way.
On the other end, once a kid is out of that impressionable phase and is able to formulate independent opinions, I might consider a religious school if there were no better secular options around. I am hoping here that my child would have a very good filter in place, and questions many things (even me). So it would probably be an infancy and/or high school thing, with very little in between.