I have read that in the past, they did not charge to set up chair sashes and centerpieces. It's very frustrating if they changed this. If they are going to charge per chair sash, I will have someone from my family tie them. I'm not going to pay $2 per bow. We have already blown our budge by several thousand dollars.
I also read that you would need to double the amount of sashes because they will not transfer the bows from the ceremony to the reception because of time. So maybe this has changed, but I am planning on doubling up on my sashes because of this. I would not want to risk it if you think there is a chance that Cecilia could be misunderstanding what you are asking.
I have also read that they DO charge quite a bit to set up lanterns because they have an outside company do it or something like that. So even if you bring your own, they still charge a significant amount (if not the same amount). I would check with Cecilia to be sure but I think someone posted something about this recently.