By Herbert Lash NEW YORK (Reuters) -U.S. stocks rallied and Treasury yields fell on Wednesday after the Federal Reserve raised interest rates by 50 basis points as expected and said it would begin to reduce its balance sheet in June in a decision seen as less hawkish than some feared. The U.S. central bank set its federal funds rate to a range between 0.75% and 1% in a unanimous decision that gave the benchmark overnight rate its biggest bump in 22 years. There was little initial reaction to a policy statement that mostly met expectations. But when Fed Chair Jerome Powell said the Fed was not …