I say "prototypical," because the term "omnibus" has also been applied to progressions with occasional fully-diminished seventh chords and whole-step voice leading, but I get the sense from Yellin's and Telesco's writings that an omnibus progression with only minor triads and major-minor seventh chords is, if not more common, nonetheless a more idealized default definition of the progression.
Unsurprisingly, the classic omnibus is more common than the omnibus cycle, regardless of what repertoire or time period you consider. Between them, the 1998 publications of Yellin and Telesco have two examples of a prototypical ommibus cycle: Hummel's Piano Sonata in F-Sharp Minor, first movement, mm. 118–23, and Tchaikovsky's Sixth Symphony, first movement, mm. 259–63.
I have another, from nineteenth-century Norwegian composer Johan Svendsen. The first movement of his first symphony fills some of its coda with a big prolongation of A7, the dominant of D major, the key of the movement and symphony. For this big prolongation, Svendsen puts four iterations of a classic omnibus (well, two iterations, but both forwards and backwards) and a complete prototypical omnibus cycle back-to-back. It is the most "textbook" display of the omnibus idea in a single excerpt I've ever run across. Here it is in my short-score reduction. You can listen to it below: the transcription starts at 8:50.
* I nonetheless still find a little value in calling, for example, a A7-->C7 progression with contrary semitonal motion in two voices something like "an omnibus-component progression." Telesco labels a three-chord omnibus progression a "small omnibus."
