Unless you have millions of airline miles that you are able to cash in, chances are good that your bankruptcy attorney will be able to exempt the value of the airline miles (or a ticket bought with them) from being taken to pay your creditors.
Your airline miles probably are an asset though, and will need to be accounted for in your bankruptcy schedules.
Be sure to tell your attorney about them. Nothing is "automatically" exempt from being taken to pay creditors, so your attorney will have to specifically look for a way to exempt them in your state (particular exemptions which are available vary from one state to another).
How about selling some of those miles to pay your bills - just a thought. I mean, where can you go if your so broke your sticking everyone else with your bills?