Interesting new development...
I have been trying/looking at various things to try an determine why some groups show up and others dont. One of the things I did was to add myself to the database_administators group - which previously was NOT showing up with adquery or "getent group" commands. Now that I have updated the group (by adding myself), it is now showing up as expected - and it is the only thing I have changed.
Any ideas/insight?