In case Fullers are worried about fuel going up anytime soon, they need to look at the Isle of Wight ferries in the UK, who have a simple fuel surcharge indexed to Brent Crude oil (in our case it would probably be Dubai Crude).
It's interesting to note, too, that Isle of Wight residents have a 'Ferry Fares Fair' campaign. The issues for any island community, once fuel prices get to a certain level, appear to be the same.
Fullers could certainly improve their ticketing practices, too. Isle of Wight Ferries not only offer yearly passes, but the ability to pay for them by direct debit!
Given that Fullers are a private operator of our only public transport to the CBD, it doesn't seem at all unreasonable to me that they look at these options. Transport options shape our community. I'm still hearing tales of young people who can't afford to live here - the most recent was a couple who moved back to the CBD - with the money saved on commuting, they plan to save up for a deposit on a new house - on Waiheke! Of course, commuting from Waiheke may still be too expensive. It's this sort of social impact we need to be aware of.