This information provided by Lisa:

I'm not in NYC so maybe this is already widely known, but Pier 57 is part of the Hudson River Park Trust. Click here for their page about Pier 57. They own the piers and rent them out to various tenants or supply event permits for short-term gatherings. The trust is a collaboration between the state of NY and NYC -- not a private company. They should be able to tell you who held the permit for Pier 57 during the RNC:

Permit Office
Hudson River Park Trust
Pier 40
W. Houston Street
2nd floor
(phone 212-627-2020)
permits@hrpt.state.ny.us

It would also be interesting to hear who the insurance policy holder was for the event (permits require Commercial General Liability Insurance coverage of a minimum of $1million single limit per occurrence) and who paid the bill.

Lisa