All you need is a thick needle/toothpick/paper clip and touch up paint to fix that.

Step 1: Clean the surface of the car.

Step 2: Take the needle and dip it in the touch up paint, and allow light drops of paint to fall into the scarred area. It'll self level once you've used enough paint.

Step 3: Realize that it's never going to look perfect in your eyes without repainting the entire bumper.

A clear bra would have probably ate the damage caused by that impact. They're crazy durable.