I know of the Cirl Buntings of Prawl Point, Devon and seem to remember a program to release them in Dorset. I've just come back from Dorset and did see one on Stonebarrow Hill and was wondering if this is anywhere near any of the release sites.
I wasn't aware any were released in Dorset, though there was a release scheme in Cornwall which according to the latest RSPB Birds magazine is progressing well.