It appears they've tested it http://www.de-fluoride.net/1stproceedings/104-108.pdf gunshot and although the table shows small amounts, this is sodium fluoride we're talking here, not naturally occuring calcium fluoride.

Another snippet http://www.ncbi.nlm.nih.gov/pubmed/9181293

I got a reply from the company I emailed and they state that their bicarbonate of soda is not made from Trona. I've emailed them to ask whether it's made from salt and if so, is the salt fluoridated.

http://www.answerbag.com/q_view/179578?ref=W_Ask&utm_source=Ask Commercial quantities of baking soda are also produced by this method: soda ash, mined in the form of the ore trona, is dissolved in water and treated with carbon dioxide. Sodium bicarbonate precipitates as a solid from this method:

Na2CO3 + CO2 + H2O ? 2 NaHCO3