Please accept my apologies as this seems to have slipped under the radar.
The best way to handle this type of scenario is to use the “prepayment” feature against a supplier rather than a separate bank account. However, there isn’t anything wrong, per se, with the way you’ve done it.
The other option is to just enter is as a negative value on a purchase invoice when the credit is redeemed.
This post may help with this: Goodwill Credit Note for Supplier - #8 by QFMathew
Hope this helps!