On the related topic of Virgin Australia International (short haul), it would probably make BNE/OOL-AKL from marginal at best to more viable for VA now, to allow AKL codeshare connections to/from UA, for those VFR/leisure traffic not willing to use SYD/MEL.
It will likely however be a one way VA codeshare on the AKL-LAX-AKL leg - e.g bookable VA only (thus no regulatory approval required) as UA can't put their code on VA TransTasman, as they use NZ for TransTasman codeshare as part of their separate JV.