I really have no idea if
this will be of any use to you KH. It's about outsourcing and offshore, so might be applicable to your wife's situation. I haven't read much of it but there were bits and pieces that sounded like they had similarities.
Your wife should be able to work at whatever she likes because you are the principal applicant in the PR process and she is your spouse so should be free from any constraints that PR imposes on you. I'm assuming because she's got PR, she won't need a WP, therefore, what's to stop her from doing what she wants, as long as it's legal? I doubt you'd find anything on the NZIS' site relating to this issue because, if she's working for an overseas company, NZ won't benefit from her skills and therefore wouldn't be interested.