Hi,
Thanks for posting your question in the forum.
Since you want to link the GPO to two sites, why didnt you link it to these two different sites directly? Please understand that we could link a GPO to more than one container (site, domain,
or OU) in the Active Directory. Regarding the policy registry keys, it shores configuration data for the Wireless Network (IEEE 802.11) Policies. We could locate it in the following path:
HKLM\Software\Policies\Microsoft\MMC\{2DA6AA7F-8C88-4194-A558-0D36E7FD3E64}
For details, please refer to the following article.
Wireless Network (IEEE 802.11) Policies Run Restriction
http://technet.microsoft.com/en-us/library/cc738758(v=ws.10).aspx
Regarding Item-level targeting, please understand that we could only configure it in GPP settings. For detailed information about ILT, please refer to the following article.
Preference Item-Level Targeting
http://technet.microsoft.com/en-us/library/cc733022.aspx
Hope this helps.
Best Regards,
Andy Qi