We disembark from cruise ship on 6/11 but need to make our way back to Venice. Actually Mestre which is outside of Venice. I tried to find a bus company but they do not provide service on Sunday. I only found one. Royal Caribbean will provide transportation to Venice airport only for $55 per person. There are 5 of us. I also looked into a rental car and cost is close to $350 for 1 day. Any other bus companies or ideas for transportation?
Taxi to Ravenna train station then train to Venice
Why Mestre?
A train would be the most obvious choice. Is there a reason you did not think at it? Maybe tons of luggage? Mobility problems?
Be aware that You'll have to change at Bologna Centrale station and that you'll need 30 minutes for that transfer. Even if trenitalia.com says that 15 minutes are enough, they aren't.
There are trains that change in Ferrara as well