Look at the documentation pages 47-48 about configuring the PrimeClient - especially the parts that talks about adding 2 NICs. One NIC for the isolated private network (default 192.168.1.X) and the other NIC to to access the outside networks and ESXi hosts.
Thanks fredab2 - I've modified the IP address, NetMask and GateWay details for the 2nd NIC with the private network details. (192.168.1.x). The Workload VMs are reachable now.
However, if I reboot PrimeClient VM (though there is no need to reboot, but just in case), the network changes I made are lost and the previous configuration is set.
Any guidance here is highly helpful.
As Fred mentioned the instructions are on pages 47-48. If you've correctly modified the ifcfg-eno* files (per page 48) then they shouldn't be changing after a reboot. Double check you have things right there.