Kiwi bank offered me a reward credit card joint with Air NewZealand. I can earn Air New Zealand Airpoints Dollars on every purchase and access to Grabseat Thursday Special and to Koru lounge passes for every $15,000 spent annually. So it means that I can save Air New Zealand membership card annual fee. Really sweet but we already have National Bank Throughbred Gold Visa and the cashback rewards if awesome.
Don't think keeping two cards would be a great idea.