Confusion still exists around the term "Bioplastic". Some believe that they will not biodegrade because they may be derived from petroleum. Others believe that they are not compatible with recycling.
The answer is really "It depends".
The fact of the matter is that some bioplastics are engineered to biodegrade during composting or burial in the soil. Also some are engineered to be recyclable, such as BioPET found in Coke's Plant Bottle.
Below is a link to a white paper originally published by the BPI in a number of years ago on this subject: Confused by the terms Biodegradable Jan 15.pdf
Also, you can contact SPI's BioPlastics Council for additional details: http://www.plasticsindustry.org/BPC/