Oh were you using the vinegar just for keeping the slime/algae out? If so, get yourself a bottle of RV water freshener. We just use 1/2 teaspoon in our 5-gallon nipple waterer and a couple drops in our other smaller ones.
This is the one we bought many years ago at Walmart.
Vinegar basically will corrode it. Stainless steel will take longer to corrode than metal will. If you aren't seeing anything in a year though I wouldn't worry about it. When using only a tablespoon or two of vinegar to a gallon, that's pretty diluted.