Elaine Low Senior TV WriterUnite Here Local 11, the union backing laid-off Chateau Marmont workers, filed an unfair labor practice charge with the National Labor Relations Board on Wednesday, alleging that management at the Andre Balazs-owned hotel was unlawfully “engaging in surveillance or creating impression of surveillance of employees’ union activities.”The charge is the latest move in the ongoing conflict between Chateau Marmont, known for its frequent Hollywood guests, and the