I believe so, since it is Enhancing Magic. But WHM have enhanced Protect trait so you don't want to cast it, ever. Why take a spell that reduces damage by maybe 10% over 5mins, which three of your other party members can cast, when you could instead equip a spell that will reduce 800 damage on you that you can cast every 30s? Doesn't make a lot of sense.

Putting yourself in the Stoneskin rotation is very important to party structure. If you're always running with 2 WHM and a BRD, then I think you're probably running with too much support. I can't think of a single ideal battle setup where you would need a PLD WHMx2 and BRD. Drop a WHM or drop the BRD and use Cover on a WHM for MP regen. That frees up a spot for another DPS. This thread isn't really about that, but it deserved to be highlighted at this point..