Jones was convicted of raping two young women in the space of six weeks in late 2009 and early 2010.
On the later count, Iti - who was also present during the first offence - was found guilty of being party to rape.
The offending involved a worrying pattern of behaviour, the judgement said. The couple cruised around in the early hours, looking for vulnerable young women.
Lone victims who had been out nightclubbing were enticed into the offenders' vehicle with offers of a ride and alcohol.
Plied with booze and cannabis, they were driven to a secluded location and raped.
Iti's involvement was very much at the higher end of participation, said the Appeal Court. She had attempted to comfort one complainant, reassuring her that everything would be okay, in an effort to convince the victim to stop resisting Jones' attempt to have sex with her.
When that did not succeed Iti restrained the young woman to facilitate the rape.
The court said in its judgement that it was satisfied there was significant premeditation in both rapes, and a substantial disparity in age between the offenders and the victims - both of whom were intoxicated and alone late at night on the streets of Hamilton.