First of all, VMware does not like LACP, I am not going debate the LCAP vs MPIO here....just know that MPIO is better for iSCSI, and it doesn't require messing around with a switch.
One item that confuses me is the the way FreeNAS approaches this. Actually I guess it is a FreeBSD kernel thing. On a "normal" SAN a "group IP" is given to where all iSCSI initiators are pointed to, and each NIC on the SAN has its own IP, but the only one that really matters is the Group IP. On FreeNAS, one has to set up an iSCSI Portal, which is just an item saying hey: "listen for iSCSI traffic on these IPs." Each NIC on the FreeNAS has its own IP, but they have to be in "non-overlapping" subnets! Why?!? Not a big deal, but in order to get both of iSCSI NICs on my ESX host to talk to both iSCSI NICs on the FreeNAS I set the subnets to 255.255.254.0