I've seen people say it was tied to the one handed skill, others say its entirely level dependent.

Can anyone confirm one wat or the other?

I think its leveled, Just like unarmed is I believe. While werewolf attacks are super strong, after about level 20, You cant just button mash you have to be careful or they will easily kill you. I have a level 32 Orc Werewolf, cleared out an entire forsworn camp in under 2 minutes, They are crazy strong if you know how to use them.