<<Disclaimer: Verify this information before applying it to your situation.>>

I recently wrote to White Wave, the makers of soy yogurt asking them
about gluten in their flavoring.  If you have any
questions, you may email them to:
[log in to unmask]

This is their answer:
<<<Actually, the plain is the only one which does not contain vanilla.
According to the Celiac Association, alcohol based vanilla cannot be
considered gluten free. You might check with your allergist to confirm
vanilla might be a problem. The manufacturer of our vanilla has tested
for gluten and the amount (if any) is too small to register on the test.
Hope I've answered your question,
Kathryn Garrison >>>>
                             Rosalie  NJ