Are you using the same load? When you bed an action, you stiffen the rifle system, which can change your barrel harmonics quite a bit. Your rifle may not be in tune with the old load. If you are not reloading, try different loads. If you are reloading work up a new load. There are many things that could be going on. For example, when you bed a rifle you take parts off and on. You may just have forgotten to tighten a scope mount screw. Things can get missed. I have never had a bedded rifle get worst accuracy, I had one that didnt get any better. Just saying I think you have an issue that can be worked out.
I agree with J E Custom, good advice, but I would find a load that your new rifle system shoots first, then tune the action to that load. I personally like a tight front action screw (50-65 inch/lbs). Then adjust the rear action screw. Tune the load to the rifle, then fine tune the action to the load.