I am very sure.. what your fish has is early symptoms that will progress to larger growths. there are several types and variations of this viral infection. Your bass is showing clear signs of it. Many fish including bass are natural carriers of this virus but it rarely shows up. It will often express it's self when the fish is under extreme duress (I.E. environmental or physical stress) or in poor water conditions.
A salt bath in my opinion would not be a bad thing at all and could be therapeutic. This is worth a try.
