List of What Policies Require Background Refresh, Which Require Reboot
I looked (googled "group policy reboot site:microsoft.com"), but to be frank, I don't think such a document exists. Even on the Microsoft forums, the Microsoft staff point you to this link: http://www.petri.co.il/working_with_group_policy.htm
http://social.technet.microsoft.com/Forums/en/winserverGP/thread/1aed8cf6-5298-4412-9a88-77f1dd387284 (note, this was a thread from this month even).