Cronos, you must refer to the Canon Law concerning proper dispensations. There are many rogue priest and bishops. Some bishops THINK they can grant a dispensation for marriage to a non-Christian, yet they are either ignorant of or in direct defiance of the Church’s laws. A written dispensation is needed from Rome. For a non-Catholic marriage, the WRITTEN dispensation comes from the Bishop only. It must be written and signed as to not cause future confusion as to whether or not a specific marriage is legitimate in the “eyes “ of the Church. The simple “permission” from the Bishop has caused the marriage of your sister? to the Budhist/atheist is illegitimate. Sorry