Interested to know your sources for that info Saintsman. I've read elsewhere that the A330 MRTT and derivatives thereof are specifically being built with A340 wings, so that they will have the hardpoints and plumbing in-place.
I was fortunate enough to have a look at the first Aussie MRTT whilst it was being modded at Getaffe and had a good look at the CATIA drawings. Before that I too was led to believe that the wings were the same.
I suppose its not worth the cost of new jigs to have them built in-situe. Similarly its the same for the fuselage. Airbus would have made the complete aircraft bespoke if it had been worth it.