This is quite different from the Bonus Army. The Bonus Army were WWI veterans asking for a post-service pay ‘bonus’ from the Fed. government during economic hardship. A post service pay bonus was not legal or authorized. It was a thinly veiled sit-in-for-pay guised in the cloak of patriotism. They wanted to get paid above their pensions or severance.
I thought that the WWI vets had been promised a bonus by fedgov.