1 tanking vs. 2 tanking requires a fairly different strategy though.
You guys are getting to the head, that's fine, I'd say keep doing what you're doing for Phase 1.
For P2 the paladin bubble, they have both their main bubble and they BoP that can remove it too (I THINK, someone correct me if I'm wrong about this). I don't know if forbearance would be up to use both.
You also don't have to bubble "taunt" but taunt helps. How the mechanic works is that the boss waits for its swing timer to see if something is immune and then turns, so just because they hit bubble, doesn't mean the boss will immediately turn and kill a melee. have them make a macro like this:
And have one set up for his main bubble also. If he just spams that button, it will remove the buff but also drop BoP immediately so it won't ever attack anyone, if you want to macro in taunt to that as well you could I guess.
#showtooltip Hand of Protection
/cast Hand of Protection
/cancelaura Hand of Protection
How low are you getting the boss when the first wave of adds die? If your DPS is that good, you may be able to just zerg him down and ignore the second wave of adds, if the second wave spawns, just tank them as long as possible and blow all your cooldowns while the DPS finishes the boss.