I think if you are creating a VLAN, then why do you need alias? I haven't worked on 10G mezzanine ethernet ports, but I think it is a dual port on each head. I suggest you create a ifgrp single mode (failover) and add respective VLANs to it.
Example:
If you are creating vif: (single mode:Active/Passive failover)
ifgrp create single vif1 e1a e1b
vlan create vif1 10 (NFS)
vlan add vif1 20 (CIFS)
ifconfig vif1-10 192.168.10.2 netmask 255.255.255.0 mtusize 1500 partner vif1-10 nfo
ifconfig vif1-20 192.168.20.2 netmask 255.255.255.0 mtusize 1500 partner vif1-20 nfo
If you are not creating vif:
vlan create e1a 10 (NFS)
vlan add e1a 20 (CIFS)
ifconfig e1a-10 192.168.10.2 netmask 255.255.255.0 mtusize 1500 partner e1a-10 nfo
ifconfig e1a-20 192.168.20.2 netmask 255.255.255.0 mtusize 1500 partner e1a-20 nfo
Experts please chip in here.