We weren't married when my now DH was posted, nor were we c/l, but it's my understanding that basically, they don't care about the wives/families. They are posting the member. Sorry if that sounds harsh, but that is how it was explained to me. I can tell you what happened for us: DH's detachment knew that he specifically was coming before DH wrote down his list of preferred places to go. So they do write a list, but it doesn't necessarily mean anything.
Has he had the interview with staffing yet? I can't remember the exact timing (it's been 3.5 years) but I know that DH had a meeting where it was determined which province we'd be sent to, then he wrote the list, then he was told where he was posted. I believe this was all in the last month or so that he was there, but it all blurs together now
As for transfers, we're coming up to our first transfer, and I'm not sure how that goes either. Wow, I'm not a lot of help, am I? I know that they meet with staffing, and it basically depends on if the detachment that they want to go to has any openings. They have a 'wish list' that they should keep updated in case something comes up, especially if there is a specific area (ie drugs, tech crimes) that they are interested in.
It's going to be crazy, but try to have a positive attitude and belief that it will all work out. We moved from Ottawa to a bitty town of 2600 in northern Alberta, and it wasn't nearly as hard as I thought it would be! Keep busy, get out there and make friends, and you'll do fine. Feel free to PM me if you have any more questions