No, either the Improved Crit:Blunt feat
OR an Impact weapon will double your crit range from 19-20 to 17-20; these do not stack, as they are the same bonus. So the idea is use an Impact weapon until you can take IC:Blunt feat (req's BAB 8, so usually ~lvl 12), then switch to a different weapon.
AFAIK, none of the other crit range bonuses apply to wolf forms - i.e., Keen Edge, Pulverizer, Celestial Champion - except maybe Crit Rage from Ravager, perhaps Adrenaline too. Keen Edge with Druidic Weapons or Martial Arts Focus is
supposed to work, but last time I checked it was still bugged.