If Bartolomeo starts hurting those people like he did on the last island, Shanks won’t just laugh it off. He didn’t get to be a Yonkou by going easy on pirates who torture and extort the people in his territory. Shanks is a good guy but still he is a pirate.
Now even if Shanks forgives Bartolomeo for Luffy, other crew members Benn Beckman, Lucky Roo like newcomers don’t give a shit about Luffy.
They would take that as an insult and if Shanks doesn’t take action it would be an insult, you can’t just declare war against Yonko and get away with it. Now I know it’s not their actual flag like the one on their ship but seeing how other pirates care a lot about their jolly rogers, Shanks isn’t just going to take it easy.
I think Bartolomeo has to pay a price for what he did. If Luffy hears about it he is going to be pissed. I’m sure Oda is setting something up for the future.
*Theory by GodSogeking