Rear wheel bearing, can it trigger abs light?

it sure can, what you working on?

how did you know it had a bad bearing?

Was any rear suspension or brake work done recently?

The way your answer was written, its hard to understand what you mean by "But noise in rear end". What (EXACTLY) are you saying here? Also it sounds like you're saying you just replaced the rear brakes. If that's the case then check over the job done for something that was accidently done that could have impacted the "ABS" sensor.

Try cleaning the face of sensor
Make sure it's connected
Make sure the connection is clean and tight
Rule out wire harness issues
Rule wire connector issues

what?, you seen the sensor bad when rear brakes were checked?

Bearing noise was their before installing rear brakes.

ABS light came on a few weeks later.

the sensor is located in the rearend i belive not on backing plate.
you'll need to get it scanned to see what sensor, if sensor is at fault.
or drain oil out to see if there is any metal frags in it.

probably have to take it to a shop to get the computer scanned...autozone can't scan for ABS codes.
Let us know what the scan reveils.