The last couple of times I've flown in business shorthaul it has been Jaume Serra Brut Nature, from 187,5 ml bottles. (It's common for airlines to have different wines on longhaul flights, not sure if this is the case with Iberia.) It's OK but could not be called a very exclusive cava. And definitely not so good that I would let it influence my choice of airline. But no reason to avoid it once you find yourself in IB business class.