Can i manage Yosemite 10.10.2 clients with a 10.9.5 server with workgroup manager?
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...