Yep, it is more like cashback on losses. And they should consider my loss as a real one as the GOSU anniversary reward meant to be sent to our Bitcoin address directly.
I think you can verify it by checking your deposit history. if they sent the amount through your BTC address, the history should be available in your transaction.
If it is not available in your deposit history, that means you received the money like free bonuses ( i.e tips, rains, race prizes etc). As far as I know, Wolf doesn't count free money for weekly bonuses. But your wagers will be counted and you should receive some rakeback for your wagers.
Bonus codes are mainly loss-back based, wolf accounts for the gameplay from the last 7 days and based on that grant a code.
Turnover is not important at all for the weekly bonus code.