I wonder if this means I can use treasury bonds as payment at a restaurant (of course practically they would refuse, and I don't suggest trying this, but an interesting thought)
Hadn't thought of that, but I don't believe Treasury Bonds are considered legal tender nor do they instruct the bearer on it that they have to be accepted "for all debts, public and private".
As an aside, our currency used to say that they could be exchanged for the denomination in Gold (or silver, depending on the note) on demand at the US treasury.
