Create two VMkernel interfaces on two separate port groups (standard or distributed), with IP addresses in the same subnet as the iSCSI storage system (target portal). Use the following screenshot as an example:
Once done, modify the failover order in such a way that only one of the uplinks is active and the other is unused. Use the following screenshot as an example:
For port binding to work, the VMkernel interfaces and the iSCSI target portals cannot be on disparate network subnets. In other words, they should be in the same broadcast domain (VLAN). This is only a limitation with port binding; iSCSI otherwise supports routing.
There are cases when port binding should not be used to achieve multipathing. The When not to use port binding section of VMware Knowledge Base article 2038869 (https://kb.vmware.com/kb/2038869) has more details.