Twomey, who Judge Phillips said was convicted of drink-driving in New Zealand in July, was "yet another tourist who comes to Queenstown, gets drunk and gets involved in violence".
He said there was also an arrest warrant out in Ireland for Twomey, although defence counsel Mike Newell, of Dunedin, said his client disputed that.
"I guess he will find out on his return to Ireland whether it is true," the judge said.
Twomey began to cry in the dock as the sentencing progressed.
He had earlier pleaded guilty to assaulting Jacob Hoggard with a weapon (a pool cue), assaulting Cain Mann with a weapon (a glass), assaulting Sergeant Mark Gill, and assaulting bar doorman Paul Moynihan at the Buffalo Club.
Twomey and two friends were playing pool when a scuffle broke out between one of his friends and Mr Hoggard.
One of the friends grabbed Mr Hoggard and held him against the wall while Twomey picked up a pool cue and swung it at him, hitting him on the arm.
One end of the cue hit an empty glass, causing it to fly across the bar and hit Mr Mann in the face. He received a 2cm cut below his eye, requiring a night in hospital and time off work.
In a victim impact statement, Mr Mann said he was he was in a friend's wedding party soon afterwards when he had scarring and was "disfigured".
After the pool cue incident, Twomey was restrained and taken outside, during which time he attempted to strangle Mr Moynihan.
After being arrested, Twomey was belligerent and aggressive and at one point grabbed Sgt Gill by the genitals and squeezed.
Mr Newell said Mr Mann was the only person injured in the incident. However, Judge Phillips said he "wouldn't agree with that".
"I don't know if Sgt Gill has children, but I would have thought what happened to him would at the least have been a most unpleasant and painful event."
Mr Newell said he understood Sgt Gill was one of the officers who would escort Twomey back to Ireland.
"That will be an interesting 14-hour flight," Judge Phillips replied.
"I hope he keeps his hands to himself."
Judge Phillips said it would cost New Zealand about $10,000 to $15,000 to deport Twomey.
Twomey had no savings or assets, so "sad to say" there would be no point in ordering him to pay emotional harm reparation to his victims - one of them an innocent bar patron, as well as a police officer and a doorman, who were "only doing their jobs".
Twomey was sentenced to nine months' jail on each of the assault with a weapon charges, three months for assaulting Sgt Gill and one month for assaulting Mr Moynihan, the terms concurrent.
He is also banned from returning to New Zealand for five years from his date of departure.