Bubbles , if you're having g so many issues with your own job then why add to your stress worrying about what the manager is getting the Baker to do ? I genuinely dont mean to sound harsh but the manager is responsible for waste not you , if Baker does 3 days worth , whatever . Pick your battles , if I were people partner , I wouldn't listen , I'd be wondering why when you've had so many issues of your own that you're bothered about the bakery . It sounds like you checking everything that this manager does and are running to the people partner .
For your own stress levels , try to go in , do your own job to the best of your ability , document any issues of bullying against you if any occur and then go home . I understand sometimes it's hard when other people get away with everything and you seem to be pulled up on the slightest thing but for your own mental health just concentrate on yourself .