I haven't tried it yet but since Quellng Strike doesn't specify that spells don't work, while other buffs do (For example, Blindside and Blood for Blood specifically say they don't work for spells), so I'm assuming it does.

edit: Thinking about it some more, if the TP bonus activates then the Enmity down definitely is working. Quelling strike is all-or-nothing, so it's another move to consider getting, Sheranfur.