NEW YORK—Peloton Interactive Inc. subscribers have filed a proposed class action lawsuit accusing the maker of at-home stationary bicycles of improperly charging sales tax on memberships in New York, Virginia, and Massachusetts. In a complaint filed on Thursday night in federal court in Manhattan, Brandon Skillern and Ryan Corken said Peloton should have treated its $39-a-month “All Access” and $12.99-a-month digital memberships as tax-exempt “digital goods” in the three states. They said Peloton has refused to reimburse them for the 6.3 percent or 8.9 percent “sales tax” it had collected before Jan. 1, when it changed its taxation practices. Millions of dollars nationwide may have been collected improperly, they said. Peloton “willfully and knowingly overcharged its subscribers” to maximize profit, according to the complaint. The New York-based company declined to comment on Friday, saying it does not discuss pending litigation. Lawyers for the plaintiffs had no immediate additional comment. Skillern …