Regionalize it. There needs to be a transit coordination for the region that includes marketing.
Years back, Manchester New Hampshire renamed their airport “Manchester-Boston Regional Airport” and there was certainly some contention. However I remember seeing plans to coordinate flights, trains, park and rides, among Logan, Manchester, Green, Hanscom, and Worcester. Back then regionalizing made sense because Logan was so overcrowded, while the others could be much cheaper or more convenient, depending n where in the “Boston Region” you were.
I haven’t heard anything like that in years though: Logan was rebuilt to support more flights, the Big Dig and Silver Line transit made it much faster to get to Logan, plus Acela freed up the skyways a bit