why is san fransico referenced again ?

this time with ben's comparision of the new island to alcatraz.
previously we have seen pictures of the golden gate bridge in at least two different episodes.
locke's address info was from san fran when he was pulled over on the way to pot-town.

is someone invloved with the show slipping these in or could there be more ?
i don't know how the two locations could connect, if that's even the intention?
any thoughts?