This area is a toughie and a rule everyone needs to be clear on from the gecko. If the bachelorette party is a single-day event, the bridesmaids should pay for food. However, if multiple meals are involved, bridesmaids should figure out beforehand who pays.
There are lot of ways to go about this, like half the party pays for day one and the other half covers day two, or you let the bride know a certain amount of her meals (like snacks and dinner) will be taken care of and that she's responsible for the rest.