The robbers escaped on foot with the stewardess’ handbag, which was recovered later from a nearby park.
Merseyside police were called to the scene.
A spokesman said club staff were clearly very shaken, but apart from the man who was hit, other members were largely unharmed during their ordeal.
Detective Chief Inspector Richard Carr said: “We are determined to catch the people involved in this robbery.
“An attack like this is totally unacceptable.
“I would encourage anyone with information to contact us and help us bring these people to justice.”
Police are appealing to anyone who may have witnessed the incident or saw people leaving the club to contact the police on 0151-777 6564 or Crimestoppers on 0800 555111.
