Do Disney buses even have those scanners needed to read a Magic Band? I doubt that would be practical even if they could. I do recall many years ago there were restrictions on who could ride the monorail to prevent kids from joyriding around for no reason. However, the most recent time I was there, can't recall any signs that restrict its use. I have never been asked to prove where I am staying to use Disney transportation in the past several years. Even when you go through security to board a monorail, they don't ask you to prove where you are staying.