If you want to geek out over the pharmacology, ketamine is mainly an NMDA antagonist, same as the other dissociative hallucinogens, and apparently that's one of the mechanisms of ethanol too, though anecdotally I've only heard complaints about alcohol cross-tolerance issues with GABA agonists.
This whole subject is really interesting and you should at least check out some Wikipedia articles:
I had found the NMDA receptor connection, but so far not any mention of long term (four to six months) of alcohol insensitivity after ketamine use. If there is one, I'm unable to find it.
Some new information in those Wikipedia links, about other neuroreceptors.
