In my life I've met two other people with the same given name I have (and it is a rather rare one), so...
yeah I've met at least three over the years and mine isn't exactly common either, so it's hardly impossible for two characters to have the same name.
Indeed, it's a common trope in fiction to unrealistically avoid having two characters with the same, or even similar names simply to avoid confusion, where in real life it's extremely common.
Hell, when I was at school, I remember there being something like four Daniels, three Stephens, a couple Michelles, two Ricks (both with the same surname as it happened, despite being unrelated) several Davids, Helens, Christophers, two blokes called Chi and probably several more I'm forgetting, all of them in the same year (or "grade" for the sake of the yanks.)
So yeah, "Bail" may be the inner core equivalent of "John" while Antillies could be along the lines of "Smith", or be the name of a very large old royal family that married into the aristocracy of several inner core planets over the centuries, including Alderaan & Corellia. Hell, with the EU gone from continuity, Wedge's backstory is open season again so he may indeed be Alderaanian and the grandson/nephew/third cousin twice removed of that bloke in TPM. Who knows?