Dasani Water PlantBottle: Green or Greenwash?

The bottled water industry has come under fire recently for its  detrimental environment impacts and questionable consumer benefits.  Plastic bottles, though recycled to some degree, find their ways into our landfills or worse, into one of the gyres, e.g. the Great Pacific Garbage Patch.

The other day, I came across this bus shelter ad for Dasani water touting the benefits of their new PlantBottle.  It states that the newly-designed bottle is made from plastics that are derived from plant-based (hence, renewable) sources.  While it is made from renewable sources, it’s still plastic and I wonder whether it is more or less resource (energy, water, etc) intensive to manufacture the bottles with the plant-derived materials.

Given the issues swirling around bottled drinking water, is this ad any more than a campaign by Dasani to greenwash its image?