Can my sister leave the state on bond to receive drug treatment in another state?

You will need to check the conditions of bond and make sure that they do not prohibit her from leaving the state.  You should also make sure that if she does leave to get treatment that the bondsman (bonding company) who posted the bond knows that she desires to seek treatment. If she has not been indicted by the Grand Jury as yet, you might consult with an attorney to investigate where her case is in terms of lab reports, presentation to the Grand Jury and investigating the options she might pursue legally as well as for treatment and how it will impact her case(s). What you do not want to do is violate a condition of bond, or not be available to appear at her court date unless the court is aware of where she is and what she is doing in terms of treatment and length of stay.