Moments before Manchester United's goal at Old Trafford, Lukaku struck Bong with his right boot, then connected with him again with his left as they tangled at a corner.
The incident took place in the 66th minute and went unnoticed as Ashley Young's shot was deflected into the goal by Lewis Dunk, but it was captured on video and the Belgian striker could face retrospective action on Monday.
According to the 'Daily Mail', the FA have been made aware of the incident and will study referee Neil Swarbrick's report of the game before reviewing more footage.
The 24-year-old could face a charge of violent conduct which carries an automatic three-game suspension, potentially keeping him out of trips to Watford and Arsenal, as well as the crucial Manchester derby at Old Trafford on December 10.