Going by the different families (the Goths, Bachelors, Newbies, Calientes and Curiouses in particular), you can pretty much figure it out. Take Mortimer Goth for example: He's a child in Sims 3, an adult in Sims 1 and an Elder in Sims 2. Bridgeport doesn't seem to have any families common to the other games, so really it could be anything. I'd lean towards pretty modern though considering the atmosphere of the Expansion.
Like Chronic said, a lot of towns follow naturally on from each other (eg. Sunset Valley to Pleasantview), but I really can't put my finger on Barnacle Bay. If anything, it seems to be set a few years after Sims 2, judging by the Caliente sisters. The Gilsbaro family could also be related to Goopy Gisbaro from Sims 2, especially since the little girl's father is missing and her Bio says she likes cowboy things and plaid (both of which Goopy famously wore). Of course this is all speculation, and I think Chronic had a point about the financial aspect.