Personally I wouldnt wear flip flops, ever. Nevermind in the dining rooms.
Ripped jeans I have no issue with though I dont wear them.
I wear dark blue jeans all the time, and I mean all the time, with polo shirts, all the time.
I dont wear suits, no longer won one, and havent worn a tie in 20 years.
So to answer your question I wouldnt know if they would be allowed but would be surprised if anyone walked in wearing them. Although, maybe someone can explain to me the huge difference between a fella wearing flip flops with ugly toes, compared to woman wearing sandals with ugly tose?