Transportation to hotel in Venice.

Book a water taxi from airport to your hotel
Official site
https://www.motoscafivenezia.com/en/

Not sure how late the buses run from the airport to P. Rome where you would get the vaporetto. If they do run that late, my opinion is that with six people (unless four are small children) you should be quite safe. On the other hand, if you prefer, consider two regular taxis. Should be a lot less unless there is an up charge for the lateness of the trip. Perhaps a lot of google searching will give better insight.

Agree with Christine. Book a water taxi.

If I were arriving at the airport at 10 PM, I would want to get to my hotel as quickly as possible, and as easily as possible. According to their website, each water taxi can accommodate a total of 10 people and 12 suitcases. The price quoted is for four people, and from the fifth person up there is a €10 per person surcharge, so it looks like your price would be €149 for six people with the possibility that it might be €169 if your hotel is in their list as are difficult to reach so having a €20 surcharge.

We took the water taxi on arrival in Venice, and it was the best decision we made!

The bus from the airport runs to the small wee hours. It isn't a public bus with a lot of yahoos on it.
You want to understand what the ester conveyances are called. The public ones are called vaporettos, a privately hired one is a water taxi. Vaporetto tickets are under $10 Euro a person as a broad guideline, but by the time you get into the city from the airport, some routes may have stopped running.
Your hotel website should have a page with directions.
But given the timing, and the potential for dark street signs, a private water taxi may be worth it depending on hotel location.

This is great info. Thanks!. We will book the water taxi. How do you get to the water taxi from the airport? Is it walkable or we need to find transportation to get there?

You walk, but there is a moving sidewalk. Just follow the blue signs to “water transport”. Photos and instructions here:

https://europeforvisitors.com/venice/articles/venice-marco-polo-airport-moving-sidewalk-to-boats.htm

You may have to check in with your water taxi service at a desk in the arrivals area before heading to the dock. This will be noted on your reservation if required.

hey hey kcapita15
totally agree with ChristineH with motoscafivenezia.it
read about the water taxi, arrival time and dates in may. (may 15, 16, 17, 18 not available and after 11pm to 5am or a 15E surcharge, more surcharge for 5+ bags), click useful information with questions asked and answered, or send form to them for info.
always have the address for hotel/apt and directions from host/hostess from stop since it will be dark.
after receiving voucher, read it carefully, any questions call or email. i use whatsapp.com for calls within europe.
hope all works well for you and the family, we have used water taxi 4X and love it.
aloha

What is the name of your hotel? Maybe you don't need a water taxi if it is close to Piazzale Roma where the buses arrive.