I have not made a potholder, so I wasn't thinking in that direction, but if it is quilted, you may count it. The smallest quilt I have made was about 12 x 18 inches, and I counted it.
As to whether it counts if it is not finished, I have done that also. I have many that are still in progress, and every one has a number. I leave it to the individual. Many people do not keep track of how many, but I truly enjoy having a record of when and why I made each one. A hundred years from now, someone may be interested in the story behind something that came from my hands.