Fares | Metro Christchurch
www.metroinfo.co.nz
Fares and fare zones for bus and ferry transport in Greater Christchurch. Transfers, fares to/from the airport, gift vouchers, comparison between metrocard and cash.

The tl;dr is that zones are basically gone and everything is a flat $2 if paying with Metrocard.

I think this simplification will be part of the groundwork they’re doing to prepare for the National Ticketing Solution rolling out in 2024.