City law over Federal law when federal subsidies are received?

in urban housing authority buildings.. or nonprofit property management companies have federally subsidised tenants in building, and there is a question as to whether the rights of a subsidised tenant have been violated by property management not following CITY / COUNTY LAW, and who claims to be exempt from following city/county law because FEDERAL MONEY is received in the form of subsidies, who's law and what law are they bound by? the constitution? and why might a non profit property management company want to NOT follow city law and refuse to recognize it when they follow the ordinance of posting these city laws within regulation clearly in sight in the lobby area?