Most casinos have no problem when you are playing on your spouse's card.
I have hit taxables when playing on my wife's card at Rampart, Suncoast, Gold Coast, Palms, Tuscany, South Point and others. When the attendant came over I handed him/her my ID and said I was playing on my wife's card. The W2-G was made out in my name. Never a problem, except at Tuscany lately.
Over the last year Tuscany has cracked down on players who played on multiple cards, both their spouse's card and other cards. A number of players got "no mailed" for this or for just being a winning player. At the Tuscany the payback is in the mailer. No mailer = no positive play.
So, go right ahead and download the free play. I agree with Liondownnow who suggested you do the free play on a machine where the jackpot is less than $1,200. Video poker at the $.25 level comes to mind.
Good luck!
