Any property that exists (except, of course, government property) can be placed under lien, doesn't matter who, or what, owns it.<quoted text>
"His" ranch is held in a trust. I doubt that his cattle business is held by or operates under the same trust.
You can look up the property records at the Clark County website for yourself.
And by the way, if his ranch is held in trust, it would seem to me that the trust, not Mr. Bundy personally, owes the fees.