Macakigo1 -
I haven't tried this in a lab, but I think you might be able to do it.
Is multipath enabled on the host ?
Create the vlan tagged interface on the second ifgrp.
Enable jumbo frames on the new vlan tagged interface.
Configure a new IP address on the new vlan interface.
Look for the new initiator to target connection on the host and on the NetApp.
Configure the old interface down.
See also the San Administration Guide documentation:
https://library.netapp.com/ecmdocs/ECMP1196995/html/frameset.html
I'd try to lab this out on simulators before trying it out in production !
Performance can be complicated, there may be other issues involved.
We do teach offer a 3 day 7-mode performance class from NetApp U...
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant, K&H Research http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, IT Learning Solutions http://sg.itls.asia/netapp
(P.S. I appreciate points for helpful or correct answers.)