I have not used BizTalk RFID, and also not very familiar with the standards. I searched about it little bit and looks like BizTalk RFID fully support EPCIS standard, I am not if that's what you meant by PC/SC standards. some of the links to check out
http://msdn.microsoft.com/en-us/library/dd789456.aspx http://blogs.msdn.com/b/krishg/archive/2009/03/26/biztalk-rfid-and-standards-support.aspx
hope it helps