Same! Bump. My gf and I were disappointed after we levelled her hunter to 10 to find out that tame beast was bugged
Hope it's fixed soon!
EDIT:
To be a bit more specific, the problems I encountered after taming my pet are:
1) Pet's happiness level does not change after eating (a lot) of food. No increase in happiness shows on combat log and pet does not gain "Well Fed" buff.
2) Can't name the pet. It is just "Unknown". Can't buff the pet either.
3) Can't improve pet's loyalty and it remains at rebellious. After a while the pet simply runs away.
4) When I train the pet in Growl, the ability does not appear on the pet action bar.
Hope the details help in identifying if this is a bug! If it is, then it's pretty serious because it's like levelling a hunter without a pet.