You need to have your own adsense account to be paid. You get 10% of page impresions for anyone who signs up under you and writes a hub. If someone clicks on an ad that is shown during your 10% you get the revenue through google if you have account with them.
I know it is kind of complicated! But basically when the person you referred publishes a hub, 60% of the time their ads will show, 10% of the time your ads will show and 30% of the time hubpages ads will show.