
Accomodations
We compiled a list of neighborhoods, luxury and budget hotels and accommodations near the venues.
But for more choices we really suggest looking at Booking.com - so far it's had some of the best deals (even for apartments instead of Airbnb).
Just a side note: area to avoid would be between the Train Station Termini and the Basilica Santa Maria Maggiore. Piazza de la Repubblica is still fine.
Hotels near the church

A personal favourite of ours is:
Donna Camilla Savelli: it is an 8 minute walk to the church and has a lovely internal garden. It used to be an old convent and the church is still active with onsite nuns.
You can also try other hotels in the area of Trastevere or Gianicolo. Trastevere can be a bit touristy - and rightfully so...with it's cute little cobblestone streets, cafes and bars it's quite picturesque. Check out apartment rentals on Airbnb or Booking.com in Trastevere for good deals! Gianicolo is one of the best views in Rome but can be far away from the city and harder to get taxis/transport.
Hotels near the reception

We would recommend for a short walk:
Roma Luxus Hotel: very nice breakfast and tucked behind the Roman Forum.
Hotel Traiano: functional and a stone throw away from the reception venue.
Six Senses Rome: upscale modern hotel on Via del Corso and not far from the venue if you take the back entrance. Spa is very good.
Suitedreams Rome: budget hotel a little further away (20 mins walk) but within easy access of the buses running down Via Nazionale stopping at Quirinale which is a short walk to the venue. Also an easy 5-6 euro taxi ride.
For other short walk options look in the areas of Trevi or Monti.
Rione Monti

The bride's old haunt when she used to live in Rome - the neighborhood is not far from the reception venue. It's also quieter than the more touristy areas close to the Galleria del Cardinale. Now it's a bit more of the hipster area with cafes, bars and small boutiques.
Some hotels to note:
Casa Monti: trendy and beautifully decorated.
Salotto Monti: Fun hotel with cute amenities - also close to the reception venue!
Madonna de'Monti Suites: Quaint but clean and nice hotel on a quiet street.
Rione Prati

If you need quiet but still central with decent prices we recommend Prati. Also a great idea for those who want to pass by the Vatican for it's Jubilee.
Some hotels to note:
Boutique Hotel Piedra: modern and central.
Residenza Vittoria Roma: Budget hotel, clean and functional.
Please also look at Booking.com for Prati as you get some good low-budget rooms in a clean and calm neighborhood. It has some wonderful restaurants and cafes and still very authentically Roman.
High End Hotels (reviewed and approved)

For those who need a little luxury that isn't necessarily close to the venues:
Hotel de Russie: one of the bride's favourites.
La Minerva: another favourite - remodeled by the same group that redid the Orient Express
Singer Palace Hotel Rome: Located in a quiet street off the main shopping street of Rome and not too far from the reception venue!
Budget Hotels (that aren't crappy)

I really recommend looking at hotels on Booking.com in Prati.
For low cost apartments I would take look in Trastevere and Monti.
Please calculate that for 3 nights a hotel within the city center will amount to about 400/450 euro minimum. You might find better deals by getting an apartment (we saw studios in Trastevere for 300 euro for 3 nights and hotels for 350 euro for 3 nights in Prati).