New players can unlock a cash match bonus by placing a wager, and there are many different special bonus offers for existing members of the sportsbook to use when placing wagers on specific sporting events. There are more than 10 special bonus offers available to players using the William Hill platform and the offers are constantly changing. William Hill Bet Match and Sports-Specific Cash Back Bonuses However, it should be noted that you can only use the William Hill bonus offers if you are currently residing within one of the William Hill legal states. The review below looks at the same bonus features that our other reviews look at for other sportsbooks, making it easy to see how the William Hill sportsbook bonus offers stand out from the rest. Interested gamblers can quickly determine what they’ll gain by joining one option over another by looking at the bonuses available. There’s a lot that can be learned about a sportsbook by the different bonus offers available. No Deposit Bonus Codes for Existing Players.