We added "Private Client Banking" last year but ours is really more a handful of concierge type services (24/7 phone support, metal debit card, courier services, etc). We updated affected policies and procedures (BSA, wires, teller, courier, internal controls, HR, etc) but didn't adopt a separate policy.
"Private" services was immediately latched on to by auditors and regulators and became a whole separate category for testing so be sure to have your documentation and reporting ready to go. We've just started our FRB exam but I don't anticipate issues on that front. If it was more encompassing of the services outline in the FFIEC manual, we probably would have adopted a separate policy to help address the additional scrutiny.