According to a letter from the City of Union City, NJ, the City passed an ordinance on December 15th, 2015 prohibiting all short-term vacation rentals.
According to the ordinance, a hotel, a motel or a Bed & Breakfast are OK.
Just yesterday I went to City Hall, and I was directed to the State of NJ website, as it is the State of NJ that licenses Bed & Breakfast operations.
It may be of your interest to know that the State of NJ distinguishes a Bed & Breakfast from a hotel, a motel or an inn, one of these distintions is that a Bed & Breakfast is owner-occupied, and it should not have an area of less than 300 SQF. In the case that the number of guests is more than 10, then a door (instead of a window) is required as a fire escape exit. These are just some of the specifications listed by the State of NJ.
If the requirements to get a license from the State of NJ to run a Bed & Breakfast are met. The next major hurdle is obtaining something called a 'Certificate of Occupancy' (all City forms can be found at from the office of the City Clerk (Union City). This certificate of occupancy is granted according to the Zoning Map of the City of Union City, NJ. But, the definition for a Bed & Breakfast given by the State of NJ seems to be the ultimate rule here, as common sense leads me to conclude that a Bed & Breakfast is just a house in a residential area.