FOR flights to Portugal and Madeira booked before 15 May, TAP Air Portugal (071-828 0262) allows a companion to travel at 50 per cent of the cost of an adult paying passenger. For example, two people travelling from London to Faro, Lisbon or Oporto will each pay from pounds 105 return, while the cost of a return for two to Funchal in Madeira comes to pounds 150 each. The offer applies to all flights made between 2 April and 31 October.