Do business rules defined within Infor SunSystems apply to transactions created from Professional Advantage companion products (ie IPOS, Bank Reconciliation, CSB Invoicing, Receipting)?

No they don’t. These applications post their accounting transactions via an alternate posting engine called JET and thereby bypasses the Infor SunSystems business rules functionality. JET has its own business rules enforcement capabilities, through the ability to define analysis validation or defaulting rules. It doesn’t match the Infor SunSystems business rules 100% but will cover most scenarios.