I'm not sure how this can happen either as the sulphur/ rotten egg smell we used to get in wells is not likely to happen in an RV if the tanks are used or drained at times.
But also, I might question why you would choose vinegar? It really does work on a few bacteria as it is a weak acid but nearly useless for treating water as it doesn't kill most of the things we deal with.
If strong enough and left to set for enough time, the acid content might work to clean some of the alkaline mineral deposits but it's not first choice for doing much else for water.
Again, I would say it seems very unlikely but if you do have the bacteria that feeds on iron in the water suppply and makes the water smell and taste like sulphur, the treament most water folks use is bleach as the chlorine does kill the iron eating bacteria in wells where treatment is somewhat common.
When growing up,"bad wells" were just accepted as normal but over the years we have learned quite a bit about the buggers that caused the problem!
Since you are not sure what is causing the smell, I would favor doing a regular sanitize treament as if the RV had been stored. If you check any of the owners manuals, they almost always spell out how to do the treatment.