Before Bruno, the New York Bosses kept a tighter "grip" on the head of that and many of the other smaller Families. I know that Philly had connections to Vito Genovese and Albert Anastasia. During the Castellamarese War, they shown allegiance to Salvatore Maranzano. Joe Ida was connected to Vito Genovese. I am sure on some level Don Vitone was using Ida to position himself better. Once Bruno came to power, Gambino loosened the grip on Philadelphia. Hence, Bruno's Commission seat.
As Sicilians Gambino and Bruno became simpatico. So much so that I believe they truly liked each other. They were constant companions. As a Napolitano Vito didn't have that same connection I think. Although I could see him staying closer to the mainlanders like Rugnetta, etc.
A good example of this was his tight connections to Pittsburgh with the Volpe brothers. When they were killed, Genovese was instrumental in retaliating against the Sicilian Gianni Bazzano.
