Will this product bond to red brick in a below grade brick wall? (Mortar joint at a corner of wall is leaking.)

Yes QUIKRETE® Hydraulic Water-Stop will bond to brick and mortar to plug an active leak in a below grade wall. However, depending on the source of the water, it is possible that your leak will simply find another path, so you may need a different permanent solution. Please consult a local design professional knowledgeable of local building code requirements.