This should work for both rhel6 and rhel7 virthosts (with a slight delay)

playbooks/vhost_reboot.yml

@@ -52,7 +52,7 @@
     when: inventory_hostname.find('.stg.') != -1
 
   - name: halt the vm instances - to poweroff
-    command: /sbin/halt -p
+    command: /sbin/shutdown -h
     ignore_errors: true
     # if one of them is down we don't care
 
@@ -77,7 +77,7 @@
     ignore_errors: true
 
   - name: reboot the virthost
-    command: /sbin/reboot
+    command: /sbin/shutdown -r
 
   - name: wait for virthost to come back - up to 15 minutes
     local_action: wait_for host={{ target }} port=22 delay=120 timeout=900