You dont need a "bonus"
With PVP being slim as it is right now some kind of dailies would be awesome. Like in early WoW.
"Battleground of the day" will work god as soon as there are More BGs.

Ideas for how it is now:
Daily single queues. For 30 and for 50. Reward? More marks if you win. If you lose? Well repeat the daily.
Preformed groups, the same, but either with higher or lower rewards.
Or maybe "KO oponents of each race, gender, class" for special rewards daily. This would push PVP to a bit over "past past past time activity"

And might give my PVP RP FC a bit more to work with