It probably is, since in the original canon it's Kyon the one that says that ponytails "turn him on", it wouldn't be surprising this fetish was given to Haruhi for this genderswap version.
It literally means "controlled by ponytails". Ponytail fetish works there.
Attempting self hypnosis (failed)I don't have a ponytail fetish I don't have a ponytail fetish I don't have a ponytail fetish (repeat)class in sessionshaking head