Court documents show two further charges have been laid against Nattrass-Berquist and Wallace-Loretz today.
They are accused of robbing Mr Gillman-Harris of cash, a cell phone and bank card as well as unlawfully taking his $15,000 Range Rover.
Like the first, today's hearing saw a packed public gallery with dozens of friends and family in court to support the teens.
Defence lawyers may apply for bail with the High Court before the next appearance in February.
It is alleged the pair were with Mr Gillman-Harris when he checked into an Epsom motel on December 27.
Shortly after check-in, two young men left in Mr Gillman-Harris' vehicle.
An hour later he went to reception with a serious head injury and asked for help. He died in hospital soon after.
Detective Inspector Scott Beard would not comment further on the specifics of the investigation but said the victim's family were relieved arrests had been made.
Mr Gillman-Harris was a private man who worked for KiwiRail as a team leader assistant in Auckland's Southdown freight terminal.
He spent Christmas Day in Wellington before travelling to Auckland on Boxing Day.
A post-mortem examination revealed Mr Gillman-Harris died as a result of blunt-force trauma to his head but police would not say if a weapon had been used.