For an OWE I don't know. With 'normal' fares it has been my experience that trying to book AKL-SCL only (or v.v.) gives you less of a chance of securing a seat. I suppose that from LA's point of view it makes a lot more sense to sell the full SYD-SCL sector, after all there's people lined up for a mile to buy it; why would they want to lose SYD-AKL to QF?

Edited to add: yes, LA has trafic rights SYD-AKL.