The RBNZ's mandate is to keep inflation between 1% and 3%. (Image: Getty) Inflation could breach the Reserve Bank of New Zealand's target band in the September quarter, but is unlikely to spook the bank's monetary policy committee.The Reserve Bank of NZ (RBNZ) is mandated to keep inflation between 1% and 3%. Annual inflation was 2.7% in the June quarter, and economists are forecasting it to be between 3% and 3.1% in the September quarter.The RBNZ's latest forecast was for 0.9% quarter-on-quarter and 3.0% year-on-year.In October, when it cut the rate by 50 basis points to 2.5%, it noted a "...