If your domain is in the /etc/postfix/virtual table, a catch all address is easy and well documented:
bfccomputing.com anything
@bfccomputing bill
If your domain is the real name of the machine, it’s more tricky and not very well documented. Edit /etc/postfix/main.cf and set:
luser_relay = bill
local_recipient_maps =
That last one is the curve ball. Uncomment the setting, but set it to nothing. Then it just works. This is a setting that need to be refactored.