Possible Clues:

• Garment aptly named for where it's worn
• Level of public transport with more up front?
• Strapless top
• Staple of a dominatrix's wardrobe
• Top alternative to taxi rank?
• British-American bank having bigger assets
• Top deck on public transport?
• Close-fitting, strapless top without sleeves
• Perhaps top deck is better upholstered
• Push-up garment