.bashrc for postgres user

Hey folks,

Is there something I don't get about having an unusual home directory
like /var/lib/pgsql for the postgres user (in the RPM installation of
pgsql)?  I like to start postmaster manually, but I don't like to type
the data directory each time.  So I tried exporting EDITOR and PGDATA
env variables in postgres's .bashrc (in /var/lib/pgsql), but it doesn't
work.  If I type '. .bashrc' before typing 'postmaster', though, it
works fine.  What gives?

Thanks!
Steve