First keep in mind that quantum computers have not been proven to be more powerful than classical computers. Keep also in mind that "quantum computing", like "classical computing", is a mathematical model that exists outside of reality.
That said, I think the answer to your question is that the "test particle" in the pilot-wave model is always reaching its destination at the speed of light. If however you model the pilot wave with Newtonian physics and place a literal test particle in it, well, even if the particle is moving very fast, its meandering route will all but guarantee a much slower (likely asymptotically slower) traversal than the pilot-wave test particle.
Bohmian mechanics is not classical mechanics. The wave is guiding the particles. If quantum computing is based on the standard quantum formalism then it is also present in Bohmian mechanics. That's a proven fact.
So quantum computing is rather orthogonal to this.
I'm not sure how quantum computing would be explained, but if it is classical then yes, quantum computers really wouldn't provide any benefit. This brings to mind headlines recently on how so-called quantum computers could not outperform optimized classical computers on algorithms specifically designed to cater to a quantum computer's strengths. Of course, then you would have to argue whether there actually are any quantum computers in existence today, or the quantum computers that are claimed to exist are actually classical computers exploiting some quantum effects.
The D-Wave devices that you are referencing are actually quantum annealing machines, not universal quantum computers. A quantum annealing machine is to a universal quantum computer what a mechanical computer is to a digital processor.
That said, I think the answer to your question is that the "test particle" in the pilot-wave model is always reaching its destination at the speed of light. If however you model the pilot wave with Newtonian physics and place a literal test particle in it, well, even if the particle is moving very fast, its meandering route will all but guarantee a much slower (likely asymptotically slower) traversal than the pilot-wave test particle.
But IANAP and welcome corrections.