Battlemaster armorings do not carry the set bonuses. Rakata, battlemaster, and lower teirs have their bonuses tied to the shells.
Only war hero/campaign and above have the set bonuses tied to the armorings.
That's the idea. You want to keep the PvE bonuses, but use the gear for PvP. In a few Class/build combination that's more beneficial. You need BM Armorings to do it, because if you use (Elite) War Hero, you lose the PvE bonus.
But thanks SpoeMeister, that will solve my problem.