This paper explores oligopolistic pricing behaviour in the context of widespread price discrimination, as observed in domestic NZ and trans-Tasman air travel markets. These markets are of particular interest as being the domain of three substantial competition policy cases between 2002 and 2010, each involving proposals by Air New Zealand to form ‘alliances’ (cartels) with one of its competitors -- first, Qantas, and then Virgin Blue. Theoretical predictions are tested with internet-sourced pricing data covering the 2004--2006 period. It is found that market structure matters more for pricing in the ‘time-sensitive’ (business) sector of the market than for ‘price-sensitive’ leisure travellers. The implications drawn are that the regulatory authorities were correct to refuse permission for Air New Zealand's proposed alliances with Qantas, and may also be justified in their qualified approval of the 2010 proposal with Virgin Blue as a partner.