Two main senses: (1) the literal 'blue ribbon' as a top prize; (2) the brand short-form for
蓝带啤酒 = Pabst Blue Ribbon (PBR), heavily marketed in China through the 1990s.
蓝带 also names the Hong Kong / Asia branches of the Le Cordon Bleu (
法国蓝带) culinary school.