IF Metall has warned of strike action against car manufacturer Tesla’s repair shops in Sweden as Tesla is refusing to enter into negotiations on a collective agreement.
In the past, Tesla’s owner, Elon Musk, has publicly threatened workers with retaliation if they were to form a union. "Elon Musk’s business model is to avoid respecting human rights. Now he is taken on by one of our strongest unions. We must defeat the Tesla business model, and Sweden is the best place to start."
In my country the unions are also nation wide, but the rules/benefits they negotiate are sector wide. You can also have multiple unions that work for your sector
For example if you start a new supermarket the employees automatically have all the rules and benefits negotiated by unions for the supermarket sector
Most of what I read here gives me the understanding that the unions are confined from company to company and whatever agreements reached only act for company X and none else.