So transfer to BA, then to Iberia, and avoid fuel surcharges? (assuming you fly IB metal)
I see that TLV to MAD would be 25k (if you find lowest availability) and around $110 on IB. Regular cost is around $500 on IB, or $440 w/ a stopover in IST.
So w/ the bonus, it's 18k MR + $110, giving a value (if you ignore the miles you accumulate on the flight and purchase) of 2.1 cpm. Not too great, but an option.