This is far better than the union per company , because some unions get rich and powerful , and abusive , while other suffer.
I don't understand why you draw a distinction between "white collar" and "blue collar" labor. All wage labor is fundamentally about an individual or small board of directors dictating the terms of production for everyone else. The Board then makes all the decisions about what to do with the output of that production, and what to do with the profits which come from selling those outputs. Under the current economy, workers have no right to make any of those decisions, which are critical to their lives.
Wage workers should not be divided as 'blue collar' and 'white collar'. Instead, they should be united against this system of wage work. Their interests are the same: shorter hours, a better standard of living, and more personal autonomy.