As long as your RaF triple xp is still going, you shouldn't waste it on just getting teams to level 20.

My goal when I started was to get a 2 PvE teams (tank, 2 deeps), (3 deeps) to 60 and the rest PvP fun teams (3 shamans, 3 magii, 3 hunter, 3 locks).

Fortunately, I got to 60 in most of the teams. The rest, I got them to 45 by the time TripleXP ran out and just do AVs each night in each team to get their XP up.

If you get to 20 and keep doing PvE, you will burn out really fast.

I use PvP as a buffer to keep my interest in my teams and also as a nice break from PvE.

Make sure you get your teams all to 60 if you have the time, you won't regret it when you're having to do the normal amount of quests 3 times each :P