I used to be a member. First joined 2015 for NZ$29.99 and got an immediate NZ$30 voucher. By 2018 was NZ$49 with the NZ$30 voucher. Did not renew in May 2020 (CV19) and not rejoined since.
Over the years keep track of savings vs benefit. Depending on how many JQ flights broke even, made a profit and 1 year a small loss. Overall a
profit. Normally book JQ plus fare and sometimes max (for QF SC)
. Far less often a starter fare.
At times the lower seat selection fee (ex NZ flights) did not stick. Nil response from JQ to fix that.
Club Jetstar NZ is the same numerical number to join as AU, but costs less due to exchange rate (~1.09)
Had no issues using $NZ vouchers on ex AU flights.
NZ--->
https://www.jetstar.com/nz/en/club-jetstar?pid=menu:club-jetstar
AU--->
https://www.jetstar.com/au/en/club-jetstar?pid=mainnav:club-jetstar