The hotel has previously indicated that they can cater for gluten free, dairy free or vegetarian. However, it is worth bearing in mind that hotels in Italy aren't as used to catering for dietary requirements as those in the UK. So, the alternative options may be limited/repetitive and they may not have considered cross contamination, for example. For other dietary requirements, or for a combination (e.g. gluten and dairy free) it would be best for us to check with the hotel.
We pass on dietary requirements to the hotel before the group arrives. Please check though with the restaurant staff that they have received this information and that the food you are being given is suitable.