An old thread, I know, but Tennies bank is in Scott's Minstrelsy version, not given by Child because it is a collation, but anthologised elsewhere.

There is indeed a Tinnis between Langholm and Newcastleton, but this is a long way from Yarrow However, after noticing a house with a Tinnis name while driving along the Yarrow valley the other week, I consulted my map and found Tinnis Farm and Old Tinnis right next to the Yarrow. Presumably one of Scott's sources had this specific localisation.