In pop music anyway, the bassist will normally just play the V when the chord is the vii (not always, but usually).
In C, this would be a G bass over a bdim (B D F), which gives the overall tonality of a V7 chord (G B D F, which = G7).
Which works fine, as this is comonly resolved to the I; so, in theory, by the bass player playing the V, a perfect cadence has been created. Even though the chord is, in theory, a vii chord.
futures mentions this in his chord usage/family chart.