Can I use my tesco club card restaurant vouchers in any of the named restaurants?

You have to choose a restaurant to convert your clubcard points into vouchers, but my mate reckons that you can use the vouchers in any of the participating restaurants even if you chose to convert them all into vouchers for, say, cafe rouge. Is that right?Can I use my tesco club card restaurant vouchers in any of the named restaurants?
You have to choose your restaurant before you convert. Each chain has its own deal with Tesco and gets a different payment for similar vouchers.