Nobody can
apply for the SMC JSV - it is offered by INZ to an applicant with no NZ job offer, if, following interview, the CO thinks s/he is not well enough prepared for NZ life and work to be given Residence outright. The visa allows the applicant nine months in NZ to get a skilled job offer. If successful, the Residence they applied for is granted. If unsuccessful, they have to leave the country. This visa is like INZ saying, 'You don't look as if you can make it, but here is one chance to prove us wrong.'
Neither visa allows a person to sponsor their partner and children.
If on the SF JSV, the person gets skilled work, s/he can go straight from that to applying for Residence under SMC, which can include the partner and children
If on the SMC JSV the person gets skilled work, as already mentioned, the Residence they applied for in the first place will be granted, including any partner and family in the application.
Here is an old post with some more detail about the choices available with the SF JSV.
http://www.enz.org/forum/showthread....175#post480175