4.4 I'm running a series of restrictions to stop spam and I'm wondering how inbound mail is passed through these checks?

This is one of the the simplest things to understand about Postfix. The restrictions are used in the same order as they appear in /etc/postfix/main.cf and the first match ends the process. This is why it's a good idea to put permit_mynetworks as the first entry in an smtpd_client_restrictions line.