10-49 PvP gear is only 2 armor sets, 1 at 20 and 1 at 40. Part of those sets are orange though, so you can update them as you level.
Weapons are spread out a little more, but as long as you keep modding them when you level, it's the same as in PvE.
So no, it doesn't scale unless you mod it out along the way.
As in, if you are maxed out at level 15 in level 15 blue/purple gear you will be like a level 49 blue/purple geared character. If you are only in level 15 greens, then it's like you are wearing greens at 49. So you really want to keep geared up to your level if you want to enjoy PvP while leveling.
That's why you might notice some players have more HP's than you do, but they are a lower level.
Level 50 PvP is an entirely different story though.