Expedia shows the fare classes in which each segment is booked in the trip summary so you can easily verify those before paying for the flights. If you book the flights on Expedia's US website (expedia.com) you will be allowed to cancel your booking within 24 hours without penalty, no questions asked. So if you booked the flights on expedia.com you could call IB immediately after making the reservation to confirm that the fare classes were as shown by Expedia, bearing in mind that you always have the free option of cancelling the booking within 24 hours. If the first flight has an IB flight number, the transaction will show on your credit card statement with Iberia, not Expedia, so you get the 3x bonus Avios if you charge it to a BA or IB Chase card (probably not an issue if you're Spanish and live in Madrid.) The trip will be priced and charged in USD obviously.