So what the hell is JB in GTA world? I think it's GTAIV city location, because Sept 17 is Doug Houser's border Collie's birthday, a 2nd cousin to Sam and Dan.
That and I don't think Venis Beach exist in GTAV, Probably called something else. And <3 mugs are cities, always.
Mark my words, the guy the discovered the next location ( or a clue) 2 days after release.