Since there is no detailed description, it's hard to judge. But since I live in that area (Faubourg St-Jean-Baptiste), I can tell you that you're better off walking by yourself and discovering everything on your own (everything is within walking distance). Cheryl is right, almost everyone here speaks English (or they will find someone who does) and you'll get a more authentic experience by relying on your instinct. I'm pretty sure the tour will stop at some tourist traps such as the Maison/musée de l'érable... it'll be a shame to lose your 33 $ bucks there, in my opinion.
For $32.95 per person? I don't think so. Nothing about the description sounded at all interesting, and if you read the threads here, you can very easily create your own, likely much better, food tour. People in Quebec City can speak English, so don't worry about language being an issue.