Il Sogno di Giulietta e Romeo
Is on the opposite side of Grand Canal from St Mark's- near Rialto Bridge- closest vaporetto stop is Rialto Mercado (IOW not exactly a 10 min walk to St Mark's- who told you that??)
It looks like maybe only 1 bridge to cross from the Rialto Mercado dock but it is on a canal so a water taxi can get you right to the door.
4-5 min walk from vaporetto- don't know if this link will work but here are walking directions- you can search yourself on Google maps- Put "Rialto Mercado ATV Fermata" in the FROM box and Hotel name in the TO box:
https://www.google.com/maps/dir/Rialto+Mercato+ACTV+Fermata%2FStop,+Venice,+Metropolitan+City+of+Venice,+Italy/Il+Sogno+di+Giulietta+e+Romeo,+Campo+San+Cassiano,+1858,+30125+Venezia+VE,+Italy/@45.4396481,12.332217,18z/data=!3m1!4b1!4m14!4m13!1m5!1m1!1s0x477eb1db7801d825:0xae3cf2d30dc72786!2m2!1d12.335224!2d45.43936!1m5!1m1!1s0x477eb1c4b17aa2bd:0xa4758f7d47dc09d5!2m2!1d12.3317875!2d45.439549!3e2?entry=ttu
The Alilaguna Orange line stops at the RIALTO stop- this is on other side of canal from the RIALTO MERCADO stop so the Alilaguna doesn't work as well for you. You would have to cross the Rialto Bridge on foot first- not fun with luggage but not impossible either.
Your cheapest option is airport bus to Piazzalle Roma- then Vaporetto 1 or 2 to Rialto Mercado. (Buy your vaporetto length of stay pass when you buy your bus ticket)
This appears to be the only direction for arrival on your hotel's website- your hotel is in the San Polo district:
The Hotel has a private dock for those wishing to arrive by boat via lagoon.
Seriously if you want to splurge- arriving in Venice in a water taxi is the way to go.
Book it here:
https://www.motoscafivenezia.com
Don't worry about being late or whatever- they will monitor your flight as needed. Follow the signs at airport to the docks- it's all a moving sidewalk now. There will be lots of water taxis waiting- show your voucher and off you go.