You can't sue in small claims court without bankruptcy court permission which is too expensive to seek permission to obtain to be worth it for you.
Any recovery is limited to filing a claim in the bankruptcy (on a simple one or two page claim form) and waiting to see if you get paid on it. They can contest it in an adversary proceeding, but for a $250 debt that is valid, they probably won't.
You should get a notice in the mail in the near future notifying you of the address and case number and deadline for filing your claim, if you won't in a couple of weeks, you should look it up on the Internet (do a PACER search on the firm name for the bankruptcy court that serves Boston).
Some reorganizations under Chapter 11 result in trade creditors like you getting paid 100 cents on the dollar.
In liquidations under Chapter 7, general creditors like you usually get only pennies on the dollars.
Don't do more business with them until they pay not only your new amounts owed in cash but also pay you in full for work previously provided and not paid for. This will encourage them to get an order authorizing them to pay you 100 cents on the dollar.
In the meantime, try to sell the beer to someone else to mitigate your damages and keep good records of what you are paid.