Pass. Do your own. "Food tours" are for non FTCers! And $100 is outright absurd IMO. You can eat really well for $100 for 2.
The best part about Rome is you can go end to end in 30-45 minutes.
Campo di Fiore- Forno di Campo di Fiore. Grab some Roman style pizza. Eat outside by the fountain (or back across the street to Piazza Navona). There is also a farmer's market in Campo di Fiore.
Down the street from Campo di Fiore is Rosciolli. Great cured meats and cheese (60 month old Parmiggiano Reggiano). Make res for a dinner here.
Walk from Campo di Fiore to the Colosseum and you'll pass the Jewish Quarters. Grab some fried artichokes there if you want.
Near the Colosseum is one of the best seafood restaurants anywhere, Tempio di Iside. Get the sculpin or/and whole crab spaghetti. The gamberi rosso crudo and blanched scampi are good. Sit downstairs in the grotto.
No joke, these scampi were larger than the utensils.
Loop back up towards Trevi Fountain and Spanish Steps.
Cross over Pantheon to La Campana for some traditional Roman fare. One of the oldest in town. Get the grilled porcini or white truffle pasta if in season.
Coda alla vaccinara (ox tail in the style of the butcher)
Don't forget to feast on gelato.