Hi,
This is a tricky one as the FTP you are getting from the peloton is going to be significantly different from your Zwift based Power. How did you get your Zwift power numbers, your smart trainer, a power meter or Zpower? I would recommend if you are training for an event with our plans to do your power zone training on your aero bike on the trainer using our structured workouts.
This is going to give you the best approach to ensuring you are truly achieving an 80/20 intensity balance.