Gambling is a "vice" only if it consumes your entire life and harms yourself or your family. Clearly it's not doing that.
I like Bill Bennett, but I don't take my moral direction from him. Do you?
Recreational drug use is not a vice? Prostitution is not a vice? So, if you like picking up hookers once every couople months, but it's not harming yourself or your family, it's not a vice?
Interesting definition. Are you a libertarian? I think our conceptions of a 'vice' are different. Drinking alcohol is a vice, but millions of people do so without any harmful repercussions. Smoking even one joint is a vice, even though it will have absolutely no effect on your family or you. I'm not picking a fight -- I honestly think our defs of 'vice' differ.
Again, judging from Empower America's work against gambling, and finding no pro-gambling stories in 'Virtues', I just honestly think that if Bennett didn't have a love of gambling, he wouldn't hesitate for a minute to call gambling a vice, and something harmful to the family. One only need point to the loser gamblers who've lost their life savings in pursuit of a 'rush' in order to cement the idea that gambling has addictive qualitites as destructive as many 'illegal' drugs.