I'm skeptical that "pleasure pathways" needed to evolve, since alcohol is more of a systemic analgesic, unlike, say, marijuana, where a specific receptor is targeted.
My decidedly unscientific evidence for this is from watching a nature show years ago, where animals of many different species sought out and ate from a tree with fallen fermented berries. Animals including lions, hyenas, etc. All seemed to put aside their differences and have a high old time getting crocked. Even more amusing was the next day hangover all seemed to have, with the lion holding his head with his paws, and all looking decidedly unwell.
My general point here is, surely all these animals didn't evolve to find alcohol pleasurable to help them seek out food, especially the big cats, who are carnivores anyway, and surely all don't have the efficient gene for metabolising it. If there is any kind of pleasurable reward wired in for finding alcohol (besides getting a buzz being its own reward), it's got to be for something more complex than just finding edible food.