By Pete Schroeder WASHINGTON (Reuters) – A bipartisan pair of U.S. senators unveiled a bill on Tuesday that would establish new rules for cryptocurrency, and hand the bulk of their oversight to the Commodity Futures Trading Commission (CFTC). The bill, introduced by Republican Senator Cynthia Lummis, one of Congress’ most vocal cryptocurrency advocates, and Democratic Senator Kirsten Gillibrand, marks one of the most ambitious efforts yet by lawmakers to place clear guard rails around rapidly growing and controversial cryptocurrency markets. The measure would stipulate that the CFTC, not the S…