You said that a big chunk of the 1.9 trillion cost of the bill was attributable to the federal minimum wage. I haven’t seen an analysis, but I wouldn’t think that would be the case at all. Also, an increase in the federal minimum wage is far more likely to impact private employment than federal employees. I would think the vast majority of federal employees make more than $15 per hour, though I could be wrong.
Edit:
This article provides a good overview of what comprises the various costs of the 1.9 trillion stimulus package.