Likely an oversight. Dasha saltvines consume the same amount of chlorine regardless of whether they are domestic or wild. Their yields correctly take 4 times as long to be available for harvest, as intended.
Steps to Reproduce
Start on an asteroid with the rust biome. Locate one with a Dasha Saltvine in it emersed in chlorine. You will need to be quick, as Dashas tend to exhaust any chlorine in their area in a very short time.
This issue has not been confirmed by a developer yet.