Bontempelli's charge comes from an incident involving the Dogs skipper in the final term of Friday's 12-point loss to the Magpies, with the MRO handing down a $1,500 fine.
Bontempelli can accept a $1,000 with an early plea.
The star midfielder and his side will now turn their attention to Thursday's clash with Sydney in a trip to the SCG.
Mitchell joins Bontempelli in being charged with careless contact with an umpire from the fourth quarter of Friday's match, however the charge is the second offence against Mitchell this year.
That will mean his fixed financial sanction is increased to $2,500, which can then be reduced to $1,500 with an early plea.
Mitchell and the Magpies will return to the MCG next week to host Fremantle on Saturday.
No other charges were handed down from the match between the Western Bulldogs and Collingwood.
The MRO's findings follow a charge of rough conduct against Richmond's Toby Nankervis from Thursday's game that has seen the Tigers ruckman referred directly to the AFL Tribunal for a minimum three-game ban.