In order to make use of the Stripe commission payments, the user also needs to connect his/her account.
Go to My Account -> Stripe Connect -> Connect with Stripe.
You will be redirected to the Stripe website where fill out the account form.
If you are an admin in testing mode, you can skip the account form to get acces to my account directly.
If you are not connected with your Stripe account, the admin will be unable to pay you your commission.