Prediction markets for the next Legislators: Of course! Everyone gets to look at them except for the Representatives who actually have to divide their delegated votes among Legislators, who are generally asked by their own constituents not to look at those prediction markets to avoid circularity.
Prediction markets for restaurants being tasty: You could subsidize a tiny market on a prediction on whether a restaurant will be tasty to you, as you'll rate the meal afterwards, and some... tiny golems possibly?? belonging to some kind of rich merchant entity that only buys and sells predictions?? will fight it out among themselves to predict your rating. It's not clear what it would mean for a restaurant to be tastiest in general.
Prediction markets for who in your class is best in the cuddleroom: It's much harder to guess how somebody will rate somebody else's cuddleroom skills, especially while you're young enough to be in classes and there's not much data on you. A restaurant has lots more customers and ratings that the prediction-trading merchants get to see. Most cuddleroom encounters aren't rated at all! You could obviously subsidize a personal rating prediction on a sex worker just like a restaurant, that's almost exactly analogous.