My reading of the rules is that, if you book in economy (i.e. with a YxRWESC fare basis), it will book in:
NZ int:Q
NZ dom:Q
SQ:M
VS:Q (unless you pay the appropriate surchage for VS premium eco, in which case it books in K)
BD:Q
whereas if you book in business ((i.e. with a CRWESC fare basis), it will book in:
NZ int:Z
NZ dom:Y
SQ: D
VS:Z
BD: D