I didn't know about Dundee United! Tenny/tawny is, in any case, etymologically related to tanning, it seems (from OF tane). Noah Webster's 1828 definition of tawny is worth quoting:
"Of a yellowish dark color, like things tanned, or persons who are sun-burnt; as a tawny Moor or Spaniard; the tawny sons of Numidia; the tawny lion."
http://www.websters-online-dictionary.org/definitions/tawny?...
Tennyson is derived untimately from Dionysius via Denis. Saint Denis is known as San Dionisio in Spanish. He it was who supposedly walked two leagues with his severed head, giving rise to the immortal remark of Mme du Deffand: "Il n'y a que le premier pas qui coûte".