Know someone at Bungie, Get it featured at a place like ForgeHub here, or some other means of bringing it to Bungie's attention. Don't spam them via email though, as I don't think they'd much care for that. I would put it here first, and see if it's really what the community is looking for and enjoys.
Your map has to be good enough to stand out from all the other maps. And that means deciding a good layout and gameplay with interlocking to neaten things up. If you get your map featured on forgehub then you have a great chance at getting on bungie favorites. But you have to have some experience forging if you plan to get a map featured. Good Luck
Ya, mine and chrst's map "Help's on the way, right?" got B-net faves a couple days after it got featured here on Forgehub, which I think brought it to Bungie's attention. But besides that, I heard that it was beginning to create some custom game buzz between people, which is very important. If you make a map and people start talking about it outside of Forgehub and stuff, chances are it will get B-net featured, and you will only see its popularity rise from there. EDIT: But here is a bit of advice. You make maps because you want to make maps that you'd enjoy playing on. Never focus on the awards and features it could get, because if that is your primary goal then you will fail. You have to be sincere, and you have to realize that B-Faves and FH Features are only bonuses to the reward you get from creating a map that you and your friends enjoy playing.