The union representing New Haven school bus drivers said it has reached a tentative agreement on a new contract with the city and the bus company. Ben Phillips, spokesman for CSEA/SEIU Local 2001, said a ratification vote will probably be held next week. The city’s 340 bus drivers and monitors have been without a contract since June 30. The drivers recently authorized a strike if the negotiations with First Student Inc. failed. Details of the agreement were not immediately released, but the union said it includes improved language on wages and health insurance.