https://youtu.be/2ZP7K9oGRcw
I had a bad squeal so I replaced the belt and that sound went away and now I'm left with this chatter/ bearing noise can it be my alternator bearings or waterpump or even the tensioner maybe? I'm in desperate need of help thanks I highly appreciate it

 

No experience with my MINI JCW but with other cars I removed the belt -- be sure to note its routing and direction of rotation so you can install it just like it was before you removed it -- and gave each accessory drive pulley a wiggle test for play. My experience is the accessory drive with any play -- and it happened to be the water pump -- was the noisy one.

In this case I could feel and see the edge of the belt was rubbing -- it was a serpentine belt -- and that arises from the belt not tracking true and that arises from a drive with play that lets the pulley get pulled out of its correct alignment.

If accessory drive uses a V-belt a sign the belt is not tracking properly can be pulley wall that shows some kind of wear pattern that doesn't match the other wall. Hard to describe but I know it when I see it. The one side is doing most of the work.

 

Most likely tensioner, just to check, get yourself an automotive stethoscope to pinpoint the noise.