I assume they used your referral code. If not, then you won't get credit.
The rebates that your friends submitted cannot be an "Any brand" rebate. It must be a name brand rebate.
If the rebate was on an online rebate, your referral bonus won't be paid out until after the pending period, which could be 90 days.
There could be other conditions for the $10 referral bonus. If you feel you have met all the requirements, you could open a request. Be aware that Ibotta Customer Service has been flooded with requests and it could take up to a week for them to respond.
