Another data point:
I landed on F-pier during rush hours at ~4pm and had only 55 mins to terminal 2, so I did not have time to search for a possible F-gate door, just eyed cursorily but did not see anything relevant, so headed off towards gate 10C. Pushed the button and got already nervous for my connection, finally after 9 mins the bus arrived. On the wallpaper it says "bus will arrive within 10 mins".
The bus driver did not ask for boarding pass. He was very nice and friendly. Asked, he did not know if there is another gate at F-pier. It took only 3-4 mins ride to gate 61C downstairs at terminal 2.