Well firstly are you a member of any OW programs and were you a member when you took the flights? Iberia is part of OW (OneWorld alliance) so if you have aa or ba or lan miles etc... you should call the program you accumulate with (or want to accumulate with) to find out how far back they allow you to go to get miles. If you are not a member of any program I doubt they will allow you to create an account now and get credit for a flight taken in the summer. Maybe Iberia's own program but doubtful. I don't have experience with this, I'm just trying to help you get started with some info.