In TFS 2012 and TFS 2013 in the settings for TFS groups on the security
page when you click on "Add..." in the "Members" tab, you get the options
to either select a "TFS group" or a "Windows User or group".
If you don't see these two options, it can be that TFS 2010 has a
different security mechanism that I don't know of or your Sharepoint Server
hasn't been added to the AD yet.