Total bonds' agency paper is almost certainly largely MBS guaranteed by Fannie and Freddie. This is paper backed by pools of mortgages with the agency's guarantee on top of the security provided by the collateral. I would regard this paper as money good without a doubt and nothing to worry about. The gummint will never let this paper go bad.
"Neither my companion or I carry firearms on our persons. We depend on the goodwill of our fellow man and the forbearance of reptiles."
- English Bob