Well, I know that it has been specified by the Royal Air Force, or by the MOD U.K., that the two airplanes must be interoperable with each other. In terms of data links, to my knowledge, there are some intra-flight data links that are used by the F-35s, but only when they communicate among themselves. For communication with the rest of NATO, so to speak, the systems that will be used are the same.
On December 7th, 2010. See this statement in context.