Cannot create a project TFS 2012 - TF218027
Solution 1:
You need to set permissions on SQL Server Reporting separately from TFS itself.
TFS, Reporting Services and SharePoint all have independent permissions. The group "Project Collection Administrators" is internal to TFS and thus only gives access to the TFS functions, not the functions it uses on other servers.
The recommended approach is to create groups in AD (eg. "TFS Collection X Admins") in AD; and then use that group to give permissions in each of TFS, SharePoint and Reporting Services.