Drupal Rules are not working properly when check CiviCRM Contact's Subtype
I remember this issue from some time in the past, probably been on stackexchange here before. In the end, we developed a new Rules condition, provided by the CiviCRM Entity module, "CiviCRM Contact is of subtype". 

It is in the "CiviCRM" section of the options list when you choose your condition. 

Give that a try, I believe it will solve your problem. It is expecting one parameter, a Contact object. It then allows you to choose which subtype to look for.

It is possible you will have to load the contact first, and put your conditional down in the actions section of your rule. 

To load the contact, use the "Fetch entity by ID" action, and pass it 

civicrm-relationship:contact-id-a-contact:id