What are my rights if I was at a bar and cut my foot on a piece of broken glass that went through my boot?

If the owner of the bar doesn't provide the insurance information, you will need to file a lawsuit against the bar for negligence.  You can write to the owner and tell him that.

If the bar owner provides the insurance information, you would file a personal injury claim with the bar's insurance carrier.  When you complete your medical treatment and are released by the doctor, obtain your medical bills, medical reports and documentation of any wage loss.  Your personal injury claim filed with the bar's insurance carrier will consist of these items.  Compensation for the medical bills is straight reimbursement.  Compensation for wage loss is straight reimbursement.  The medical reports will document the nature and extent of your injury and will be used to determine compensation for pain and suffering.  Compensation for pain and suffering is an amount in addition to the medical bills.  If you are dissatisfied with settlement offers from the bar's insurance carrier, reject the settlement offers and file your lawsuit for negligence against the bar.  If the case is settled with the insurance carrier, NO lawsuit is filed.  If the case is NOT settled with the bar's insurance carrier, you will need to file your lawsuit for negligence against the bar prior to the expiration of the applicable statute of limitations or you will lose your rights forever in the matter.

As mentioned above, if the bar owner doesn't provide the insurance information, you would just proceed with the lawsuit; however, it would be premature to file your lawsuit before you complete your medical treatment and are released by the doctor in order to know your total medical bills, total wage loss and to have obtained your final medical report.  Of course you do want to file your lawsuit prior to the expiration of the statute of limitations, otherwise you would lose your rights forever in the matter.

You can't get his insurance company information or file a claim with his insurer unless he cooperates. If you feel you are owed compensation but the other party will not provide it  or cooperate, your solution is to file a lawsuit. Before doing so, bear in mind:

1) The bar is not liable, or responsible to pay, simply because you were hurt in the bar. They would have to have been at fault in someway, such as by not cleaning up broken glass of which they were aware. But if not at fault--say, another customer had dropped a bottle or glass and no one reported it to the staff to clean up--they are not liable.

2) You can only recover an amount equal to  medical costs, lost wages, and, for serious injuries, pain and suffering. It may be that a lawsuit is not economically worthwhile, even if the bar is at fault.