Why is the synbiotic relationship of wombats and snails are mutalism?

The relationship between wombats and snails is not mutualistic, but rather commensalistic. In commensalism, one species benefits from the interaction while the other is neither harmed nor benefited. In this case, the wombats benefit from the snails' burrowing activities which help to aerate the soil and improve drainage, making it more suitable for the wombats' grazing. The snails, on the other hand, neither benefit nor are harmed by the wombats' presence. Therefore, the relationship is commensalistic, not mutualistic.