You have to win hotspots to move the bar and win the zone. 1st time time you win it, the powers are a bit naff, if you win in 2 times in a row you get access to additional powers which are a bit more juicy. It can take a long time to win enough hotspots to move the bar much though 
My MA IDs:
Fiend Space: 211464
Thx, this bar I take it is near the part that says your current bounty ect?
yep, the blue/red one.
My MA IDs:
Fiend Space: 211464
I know that temp powers are given to the side who are "in control" of the zone. What effects this control and can I see progress made in the form of a meter?
The ingame text is ambiguous, it could either mean winning hotspots or successfully completing PvP missions (like bomb the base ect.). Which is it? I was finding some of the temp powers invaluable in PvE.
I searched for my answer but I couldnt find it after searching the forums and the prima guide.