Most companies need exactly one integrated, holistic Product Vision — splitting vision by team or product line defeats its purpose as a single north star. The exception is very large companies with genuinely separate business units, e.g. Amazon, where AWS, retail, and Alexa each warrant their own vision because they serve different customers, markets, and revenue models under one mission.
Amazon is the textbook exception: AWS, retail, and Alexa are functionally independent businesses with their own customers and economics, so each carries its own vision rather than being forced under one. Most companies aren't Amazon — if you find yourself justifying a second vision, check whether your "business units" are actually separate companies or just teams.