When is the Hotel Bonus Token removed from the board?
A) Stays on the board until game end.
B) Removed with the purchase of the first 5 train when the Privates close.
C) Removed with the purchase of the first 6 train.

In the absence of an actual rule (no mention under the Harriot Milton Hotel section on page 17), we assumed 'B' but upon further review 'A' seems just as likely. If the designers were going for something similar to 1870's port and cattle tokens, option 'C' would be correct.

It stays until the end of the game.