Air NZ programme is really only useful if fly NZ regularly. No lifetime status, but if fly NZ a lot can get banked years of status. I currently have 12 banked years so will have *G for current year, next year already requalified, 12 more years, then soft drop to gold (also *g) equals 15 more years not counting any future requalifications.
NZ banked years are my *a *g plan c. Plan a was SQ lifetime pps which was withdrawn about 2 years before I would have qualified. Plan b is Oz platinum which is lifetime status, but Oz unlikely to remain in *a when KE takeover completes.