Two out of turn promotions is gonna look mighty good there. One of the profiles that B-schools love the most is what we call "the shooting star" - lots of promotions, very quickly. It shows that you are gonna be someone.
Secondly, and obviously a lot will depend on your GMAT score. But you already know that, soooo I won't nag you about that
Other than that, there are other factors to look at, most importantly: Leadership. And usually we try to get more than leadership in a matrix, but some real hardcore people leading, whether it be at work or at another place (i.e. school, church, sports team, etc.) We just gotta show them that you are the type of person who knows how to do this. That you are a natural.
Other than that two factors that can change things are a) your age b) how much community service you got.
I hope this helps answer your questions!
If you like the post, give it a KUDOS!