Will we be able to hack the anti-air defensive towers on bunkers?

"Probably? Eventually." The place they want to do it first is the Comm Arrays, whether that's creating a blind spot in their defences for the Player and their party members, or perhaps turning those defences against the Security Forces. Luke imagines that's going to be one of the first places they do that sort of thing, but for bunkers it wouldn't be too different from what they imagine they'll do for the Comm Arrays, so it's definitely feasible.