THE Venezuelan airline Viasa is now part of the Iberia group, and its new Spanish owner is offering some spectacularly good deals on Latin-American itineraries. Between now and the end of August, you can fly from Heathrow to Caracas, Quito and San Jose, capitals of Venezuela, Ecuador and Costa Rica respectively, for just pounds 595. The same fare applies to a London-Margarita Island-Santo Domingo-Havana-Caracas round trip. Better still, the fare for both routings falls to pounds 525 on 1 September. But the only way to pay these fares is to call Iberia Group Reservations on 071-830 0011.