Hi
Westminster is certainly NOT in the sound of Bow Bells. However, sometimes the boundary of the Bow Bells has been argued over time. Dick Whittington said that he could hear it as far away as Highgate, which would make Islingtonians, Stoke Newingtonians and Camden Townies Cockneys. Bermondsey is known to fall in the Bow Bells area.
Great Titchfield Street is just west of Tottenham Court Road and just west of the parish boundary of Marylebone and St Pnacras.
Ben