That's a good question and honestly it didn't occur to me to test this. I tried to visit at least once between landings and I even wrote down the numbers but mostly to make sure that multiplication was taking place. I was also collecting passengers and coin from fast buildings and landing guest planes (which aren't affected by this bonus) and that required a lot of going back and forth. Will definitely keep this idea in mind next time I try this though. Sorry I couldn't be more helpful, hope someone else would pay more attention and post here.