This is probably well known. Being in Ilum PVP area puts a buff on you that gives you up to 200 extra valor per warzone completion
HOWEVER, once you leave the WZ, the buff disappears. Easy way to fix this. Run to the cave that's on the east side of the Ilum PVP area. As soon as you get close to the cave, you will get completion for all the Ilum objectives as you are technically leaving the PVP area. Once this happens, just run back into the Ilum PVP area again, and your buff reappears.
The extra valor doesn't show up on your win score. It just adds it directly to your valor.
Hope this helps someone. The cave makes it easier to regain the buff.