I never understood, apart from it just being a funny part, why Uhura & Chekov didn't know where Alameda was either since both would have gone to Star fleet Academy right across the bay from it.
It was mentioned that they didn't know based on 23rd century landmarks not being there. I don't buy that since Alameda would always be to the east. I live in Dallas and have never been to Houston but I could still find it.
The only thing I could think of is maybe Alameda wasn't there anymore due to an earthquake or it was possibly renamed sometime between 1986 and 2286.
It is funny though that the navigator was lost, haha.