I am a little concerned about where my financial information goes, so when I asked Vanguard this is what I got.
In June 2012, Bank of New York Mellon (BNY) absorbed the cash management side of the business from PNC. The account number and routing information were never changed, so the transition from PNC was essentially seamless. BNY was (and still is) always in the background processing and clearing all of PNC's transactions. Also, PNC is still the bank our clients can "walk up to" and withdraw money out of the ATM without any surcharge.
In some instances, when routing information is needed for ACH transactions or provided to a third party, it may still populate with the bank name "PNC," which is technically correct because PNC is still the bank that can be used for surcharge-free ATM transactions. For the purpose of VanguardAdvantage accounts, PNC and BNY are basically one and the same.