To get the "R50 Refer a friend" Bonus you need to follow these steps from User Menu: "Refer a friend" --> read carefully and "Accept" to activate the offer --> "Invite a new friend via SMS" or "Invite a new friend via Facebook". You can invite as many friends as you want.
You can see it by pushing the "My invited friends" button and choosing the friend's mobile number.
Your friend needs to start wagering with YesPlay on Lucky Numbers.
Not necessary. With the R20 your friend has deposited initially he/she may win, for example, R230. As long as your friend wagers this R230 you will earn your R50.