Hi,
I don't think System Manager 1.x supports vFilers at all.
This is what has been said about v. 2.0 (which is still in beta):
"vFiler scoped administration is not supported in System Manager 2.0 , currently what is allowed is we can create/edit/delete a vFiler unit from System Manager , we cannot add or discover a vFiler IP from System Manager and manage it like physical filer . We will definitely consider the feedback on adding vFiler when scoped administration is implemented in System Manager."
http://communities.netapp.com/message/53761#53761
Regards,
Radek