Personally, I think Philadelphia Ballet does sound less provincial — not inherently, perhaps, but by association and tradition. The Cleveland Orchestra is not the Ohio Orchestra; the BSO is not the MSO; Houston Grand Opera is not Texas Grand Opera; Lyric Opera of Chicago is not Lyric Opera of Illinois; San Francisco Ballet is not California Ballet, or even Bay Area Ballet.
Major performing arts organizations in major cities tend to be named for the city they're in, not the state or region. (Perhaps it's a way of signaling something about the prominence of the city and, by extension, the organization. I'm not sure.) Those that aren't are often more regional companies/ensembles, with less prominent profiles. There are probably exceptions, but I think there are far more examples that fit the "rule."