A tentative labor agreement between Boeing Co. (NYSE:BA) and one of its largest unions has left many workers dissatisfied, ahead of the crucial vote. What Happened: The International Association of Machinists and Aerospace Workers, representing over 32,000 employees in the Pacific Northwest, announced the deal with Boeing on Sunday, reported Reuters. The announcement boosted Boeing’s shares on Monday. Jon Holden, president of IAM’s district 751 and lead negotiator, stated that workers are upset, hoping for higher wage increases and better pensions. The union members are set to vote on the deal…