My secular sponsor found me...a mess...at a convention. Just got to talking and I told him I felt lost and desperate and had recently been let go by my sponsor. He said he would sponsor me, and forward we went!
We share a lot of similar beliefs, but really it didn't come up much in our step work so I wouldn't say it's much of an issue.
I have found generally that when the subject of religion and specific faith doesn't come up, when we focus on the steps...it's pretty much a non issue on either side, but when someone brings up religion, or starts asking religious questions, one or another or both sides get sidetracked in defending, explaining or critiquing beliefs.