Streisand wore a body mike. A number of other star performers had preceded her in wearing body mikes on Broadway. As far as I know, no one else in the cast wore one. I think some book or article implies that everyone was miked, but that would have been bizarre on Broadway in 1964, and I think it is not true.
Floor mikes came along fairly early in the careers of Merman and Martin. Martin may have been the first person to wear a body mike on Broadway. That was in Peter Pan, but (if we can trust what she said) it was turned only when she was flying. She was also wore one in Hello, Dolly! on tour and elsewhere, and I believe she wore on in I Do! I Do!