Actually we have no idea where, specifically, that scene takes place. It could have been anywhere in San Francisco.
Well, we know that the crew splits up at the junction of Columbus, Kearny, and Pacific Avenues in San Francisco. Chinatown is practically right there, just a block or two to the west, where Sulu, Bones, and Scotty could walk in the few minutes while Kirk and Spock were trying to board a bus.
... who but real San Franciscans (which I obviously am not) would even recognize where that scene was in the first place?
Not a Midwestern boy like me... but I can Google the TVH filming locations and check Google Maps to learn their relation to Chinatown.
