I've joined forces with the hobbyDB team to create a database of every Starbucks Mug ever made! You can use hobbyDB to manage your collection and wish list, show it off, find values for your mugs, and to trade, buy and sell. We currently have four volunteers and would love to have more join the team. If you'd like to help, contact the guys at hobbyDB.
Starbucks City Mugs 
I would like to know how to get hold of an auckland and wellington tumbler.
You can try to see if anyone is selling them on Ebay..or ask on the Facebook page if anyone has them and can trade or sell them to you.
https://www.facebook.com/pages/Starbuck-City-Mugs-Collectors/237577116304434