If you had a bankruptcy in the past you may still be eligible for a VA loan. If you are already in a VA loan you are eligible to do the streamline refinance at any time as long as you are current on your mortgage.

If you are trying to purchase a new house and the bankruptcy was discharged more than two years ago, it may be disregarded.

If the bankruptcy was discharged within the last 1 to 2 years, it is probably not possible to determine that you are a satisfactory credit risk unless both of the following requirements are met:

you have reestablished satisfactory credit, and
the bankruptcy was caused by circumstances beyond your control (such as unemployment, medical bills, etc.)
If the bankruptcy was discharged within the past 12 months, it will not generally be possible to determine that you are a satisfactory credit risk.