Thanks heaps.
I've realised that I can use the follow_link method to get a reference to the host as
well as below:
...
vms_service = connection.system_service().vms_service()
vms = vms_service.list()
for vm in vms:
vm_service = vms_service.vm_service(vm.id)
if vm.status == types.VmStatus.UP:
vmhost = connection.follow_link(vm.host)
print("{0:<30s}{1:<30}{2:<30}".format(vm.name,vmhost.name,host.name))
connection.close()
...