Is feminism a trade union?

I've never understood why some people describe feminism as a trade union. What does a trade union do?

• Provision of benefits to members - in a similar way to Friendly Societies
• Collective bargaining
• Industrial action
• Political activity

Does feminism do any of these things? Political activity perhaps but that's about it. Feminism in the 21st century is much too diverse to be considered any sort of organised activity. As women don't have one employer or one type of work I can't really see how anyone can think of it as a trade union. http://www.theantifeminist.com/ has a bee in his bonnet about this and seems to think referring to feminism as a trade union is to insult it.

Sidney and Beatrice Webb's definition of a trade union is ' a continuous association of wage earners for the purposes of maintaining or improving their conditions of employment' Does this really fit with feminism? Individual women may belong to a trade union to do with their employment but are we saying they are also 'employed' in their private lives? If so who by?