Honestly, I don't know. It should, honestly. I don't have the Companion which details how PV is calculated. I suppose I could run a tank in the latest MML and test it out.
Quick boot up and took a Patton which starts at 28 PV, and moved its AC and LRM to the Front run, and its PV stayed the same. That could be a missing conversion point in MML, or something that just isn't covered in the Companion.
Just checked, & neither trait gives a boost to PV. Probably because TUR just means that some of your preexisting weapon damage is located in the turret & can be fired outside of the normal arc (but reduces any standard damage you do), so the damage has already been calculated. For REAR, although the damage isn't included in the PV calculation or the regular damage, I'm guessing that the +1 penalty to fire to the rear is maybe the justification for not including it in the PV calculations. Not to mention that I'm guessing that, since you have to have them directly behind you to use it, adding the extra 1-3 PV points for the ability (as I would imagine most of them are either REAR1 or REAR1/1) might not actually correspond to an actual increase in effectiveness on the playing area.
Still kind of torn about whether to include it, but I suppose you could call it a special-case version of REAR#/#/#, where you'd have to also track the additional specials of any arm-mounted weaponry specifically (just like what's done for TUR). You'd still have the +1 penalty, & you could
only use it against attackers whose damage is going to hit the rear hexside of your mini, but it would add a little something extra to the game...