Spain/Portugal/Gibraltar - Vega Sicilia from Valladolid or Madrid?

Anyone know of any tour companies that offer day trips from Valladolid or Madrid into the Ribera del Duero region? In particular I'd like to visit the cellars of Vega Sicilia but don't want to drive myself.

I found these tours on line
I have no personal experience and cannot recommend them:

http://www.gomadrid.com/tours/wine-excursion.html
http://www.cellartours.com/spain/wine-tours/luxury-ribera-del-duero-weekend.html
http://www.vinophoria.com/riberaTours.htm

this looks like an interesting discussion:
http://www.fodors.com/community/europe/winery-day-trip-from-madrid-171196-2.cfm
http://www.tripadvisor.co.uk/ShowUserReviews-g187514-d1740365-r118781533-Vintage_Spain_Rutas_de_Vino-Madrid.html