As far as the dedication plaque goes, I take it with a grain of salt. I don't believe the Enterprise was built in San Francisco, California either.
Who said it was built in
San Francisco, California?
However, that's where Starfleet Headquarters are located so I think it's fair to assume that you have the bulk of the orbital stations and dockyards located in a geostationary orbit over San Francisco, CA, and not on the other side of the planet.
And the addition "California" merely states that these dockyards are not in orbit over the San Francisco of Argentina, Columbia, Honduras, Guatemala, Mexico, the Philippines or Spain.
P.S. I'm aware of the concept of changed premises and intentions. Is there evidence that the TOS producers changed the "Starship Class" concept during the original series?