He said in the face of the altercation, staff contacted emergency services immediately to look after the security of the customers.
"Going forward, management wants to make it very clear, gangs are not welcome at Ponsonby Rd."
He said the bar would increase security "immediately" as a safety precaution and there would be a zero-tolerance policy for gangs and gang behaviour.
This was in line with the bar's zero-tolerance approach to bullying, harassment or violence of any kind, he said.
"Our commitment to maintaining a relaxing and welcoming atmosphere for locals and tourists alike will not be broken in the wake of Friday night's incident."
Waiariki MP Tamaki Coffey said he fully supported small businesses to create their own rules, within the law, that delivers the best and safest experience for their customers.
"Ponsonby Rd are not saying individual members are unwelcome, simply that they do not wish for negative gang behaviour to become part of their business. I think everyone in our community can respect that," he said.
Police said the full circumstances of the assault were still being investigated and they could not give any further information at this stage.
A Lakes DHB media spokeswoman confirmed two males came to the Emergency Department early Saturday around the same time.
She understood they were from separate and unrelated incidents.
One teenage male was treated and discharged and a second young man was in a stable condition in hospital.
The arrested man is in custody and will appear in the Rotorua District Court on Monday, police said.
