The base number of Workstations that come with the Enterprise or Global license is two (2).  This is the number of concurrent Workstations meaning the number of Workstations logged into Intelli-Site at any one time.  There is no limit to the number of installations of the Workstation, only the number of Workstations logged into the Server at a time.  The Workstation on the computer where the Server is running is included in the logged in count.