Although the state censuses of New York are not indexed by name, it is fairly easy to find an individual in the enumerations for New York City if the address of residence is known. The book compiled by the Family History Library is an index to addresses for the Manhattan 1915 census. Prior to 1914, the Bronx was part of New York County and the Bronx is included in the Manhattan 1905 census and index. The Bronx was enumerated in 1915, but was not indexed by this card index. Addresses can usually be obtained from city directories.
Most city directories for New York City are available on microfilm.
Manhattan directories for this time period also include Bronx addresses. Once you have addresses, then select one of the street address indexes. This index was filmed at the office of the New York County Clerk but it is not open to the public at that location. For each address, the index provides the assembly district, election district, and page number. There are usually two numbers in the assembly district column.