Yes.  To create an agency-wide location, set the program selection option to "All Agency Programs" during the location configuration process.

Each location name must be unique, regardless of whether a single location is used by more than one program.  If multiple programs must use the same location, you can use a simple workaround, such as adding a punctuation mark to make the location slightly different in each program (for example, "Conference Room A" and "Conference Room - A").