It would seem that not only does the whitelist not function when there are multiple recipients, but the entire user_prefs and bayes database are not read, because SA does not know what user it is dealing with.
/var/log/maillog shows the following:
spamd[39771]: spamd: identified spam (5.2/5.0) for (unknown):65534 in 3.3 seconds, 25007 bytes.
Therefore I have no choice but to disable SA at present, because it is tagging/ deleting so much valid email. <sigh>
-Swift