Ah, yes, if the companies needs can be met only with smart property, then sure. That sounds unlikely though. Most companies biggest cost is wages, not assets.
A bond market with completely anonymous participants has to rely solely on reputations (as it doesn't really make sense to buy a passport/fidelity bond/etc to borrow money). I'm not sure that's tractable in the real world for the same sorts of reasons that the web of trust never really took off: barrier to entry is too high.
People value their physical identity as an asset because everyone is given one for free at birth by their parents and the state, and because it can be used to easily put your own personal freedom and all assets on the line as collateral in a deal.
The vouchers/colored coins can be used for smart property and/or wages. In the case of wages an employee gets vouchers that he can use to purchase goods at stores. The stores can then swap the vouchers for bitcoins. However if the bond issuer breaks his contract the vouchers he pays out will no longer be exchangeable for bitcoins. Its a slightly different scenario from purchasing smart property but the underlying goal of keeping the bond issuer honest is the same. With the voucher system described the barrier to entry for the web of trust would be lowered, you would have to trust people, but there would be that safeguard of the vouchers and smart property.