James Bregenzer, a 31-year-old marketing strategist in Chicago, was rejected for a mortgage in May after successfully financing two previous home purchases. Bregenzer is in good company. “We asked if we could go over by $100 and were told that’s just not going to work,” said Bregenzer, who bought his first home before getting married in 2008. Lenders are continuing to tighten the credit vise on homebuyers after five straight years of economic expansion, imposing the toughest standards since at least 1998, according to a new index by CoreLogic (CLGX) Inc.