A Translink inspector was allegedly struck on the head with a bottle by a passenger he had previously fined for being on a Glider bus without a ticket, the High Court has heard.
Prosecutors said the victim suffered a significant ear injury which required 11 stitches and had his glasses broken during the attack in west Belfast.
Details emerged as bail was granted to one of two men accused of involvement in the outburst of violence on June 7.
David Molloy, 31, of Lagmore Dale in Dunmurry, faces charges of common assault, criminal damage and possessing Class C drugs.
The victim, a customer revenue protection officer, was attacked onboard a morning Glider service in the Andersonstown Road area.
Crown lawyer Adrian Higgins claimed Molloy's co-accused recognised the inspector as having fined him for having no ticket the previous day.
A struggle broke out which led to the employee being punched up to six times and spat on, the court heard.
At one stage those involved in the scuffle fell on top of another female passenger.
Mr Higgins said both men were ejected from the bus but continued attempts to get back on.
"The co-accused swung a glass bottle and hit the injured party," he submitted.
"As a result, the Translink staff member suffered a cut to his ear which required 11 stitches in a very significant wound."
The bottle was then wielded again to smash a door on the Glider, according to the prosecutor.
When Molloy was arrested police found seven suspected Diazepam tablets on him.
His barrister, Joel Lyndsay, argued that the co-accused faces more serious allegations of wounding the inspector with the bottle but has already been released from custody.
Granting bail to Molloy, Lord Justice Maguire ordered: "He is not to use any Translink services."