Ms Ross said her partner was "unrecognisable" when she first saw him in hospital and for months she took time off work to care for him.
On September 7 last year, Tauatevalu and his wife attended the Otara Scorpions rugby league prize-giving at the Manukau Velodrome where an argument developed over her speaking to another man.
After reports of a violent argument, Mr Tate pulled them over down the road from the venue.
He tried to speak to the woman but the offender intervened.
At trial, Tauatevalu's wife gave evidence of her husband upper-cutting the officer several times and said he looked as though he had "no life in him".
Other witnesses who were on the scene shortly afterwards told the court how the man repeatedly stomped on the officer's head as he lay on the floor.
Justice Graham Lang detailed the injuries suffered by Mr Tate, which included a broken cheek bone, nose, eye socket and larynx, as well as bleed on the brain.
The judge described the attack as "wholly cowardly and produced devastating results for the officer".
A report by a psychologist stated the victim might never be fit to return to work.
"The offending sends ripples beyond the immediate victims. They send a message of concern to the police force as a whole," Justice Lang said.
"Police officers have to know the court will stand behind the Crown when they bring charges such as this."
He gave Tauatevalu credit for admitting the offending and expressions of remorse which came as early as his first police interview.
However, the judge said the defendant's clear anger management issues meant there was a need to protect the public.
He imposed a minimum non-parole period of three years three months.
