I work at a university and a professor running a lab would like to keep Workgroup Manager but run Yosemite clients. I can not find any specific documentation on this. Except : "Note: Workgroup Manager and previous versions of Server app are not compatible with Yosemite." But I believe that is just that there is no Workgroup Manager that runs on a Yosemite server.
It doesn't look good. See [this topic] for more info. : apple.stackexchange.com/questions/151886/…– smoooosherMay 19, 2015 at 19:12
Late answer but I thought it might help. Yes, I believe you can still use WGM to administer / set prefs on Yosemite clients. But you should keep your server version as is. I still have OS X Leopard Server running as OD master and WGM for all my client machines running OS X Yosemite. I also use Profile Manager alongside WGM and it works without problems...