I have recently subscribed to Photographer's CC and installed the software on my desktop PC and laptop PC under the terms of the EULA...OK
If I were to change my desktop PC to a Mac could I install one version on that and keep a PC version on my laptop. I know that I would have to de-licence the current desktop (PC) version first.
You may install software on up to two computers. These two computers can be Windows, Mac OS, or one each.
If you install on a third computer, it requests that you deactivate on the other two computers. You can then reactivate one of the previous two computers, and use Creative Cloud apps on it.
For more information please check the FAQ document of Creative Cloud: - http://www.adobe.com/in/products/creativecloud/faq.html
Do let us know if it helps.