As General Motors Co. prepares for its electric vehicle future with multibillion-dollar investments in Lansing, Orion Township and elsewhere, autoworkers worry about the growing number of employees making less than traditional union-represented employees at the Detroit automaker. They see the push to add more jobs at subsidiary GM Subsystems Manufacturing LLC and GM’s joint venture battery cell manufacturer Ultium Cells LLC as unmistakable moves to retain a tiered wage system the United Auto Workers fought hard to eliminate. “When they say they got rid of the tiers, anybody outside of GM would…