As far as I'm concerned, you can apply whenever you see a position open. It's usually on the boards in TMSC or you can check online through EHR.
Don't quote me on this, but if you're a new team member you may have to be in your position/work center for the first three months before transferring to another work center, position, or store. I'm not positive on that though.
I thought you had to be beyond 90 days but we recently had a TM promote to TL that had only been there about 60 days, they did have previous TL equivalent experience so maybe that had something to do with it? that and our store is currently like 3-4 TLs under headcount