In the default config, ~/.spamassassin/bayes_journal cannot be a symlink,
because it is deleted if it is a symlink.  The other bayes_* files can be
symlinks, they are followed as expected.

I used the following workaround,

    /etc/spamassassin/local.cf:bayes_path ~/.spamassassin/bayes/bayes

where ~/.spamassassin/bayes/ is a symlink.  However, this workaround is
a bit heavy handed, since it forces all user's bayes_* files to be located
in the ~/.spamassassin/bayes/ directory.

Thanks,
Jeffrey Sheinberg