Members of the Unite union endorsed industrial action at a rate of more than nine to one Saturday, although strike dates have yet to be announced.
The union is seeking a 500 pound (approximately $775) bonus for working over the games for each of the 20,000 bus workers it represents.
It's the latest group of transit workers to demand extra money to work over game time.
London's subway train drivers have already secured one-time payments of around 500 pounds for working over the games, while those who run the capital's bicycle rental network have also asked for bonuses.
The games run from July 27 to Aug. 12.