NEW YORK — Amazon and the nascent group that successfully organized the company’s first-ever U.S. union drive are headed for a rematch Monday. A federal labor board will tally votes cast by warehouse workers Monday in yet another election on Staten Island. A second labor win could give workers in other Amazon facilities — and at other companies — the motivation they need to launch similar efforts. It could also cement the power and influence of the Amazon Labor Union, the grassroots group of former and current workers that secured last month’s historic victory. But a union loss could mute some of the labor celebrations and raise questions about whether the first victory was just a fluke.