First, wheel end vibrations are mostly felt in the 50 mph to 70 mph range. Outside that range, the vibration is hardly felt.
Why that range? That's because Spring-mass-damper systems, such as a vehicle suspension, have resonant frequencies where vibrations are largely uncontrolled - albeit at a different angle from the vibration source. In cars, this occurs in the range mentioned above - with a few exceptions. (editorial comment: Why are there always exceptions?)
Second, a separation causes a vibration, so it reacts just like an imbalanced or out-of-round tire (After all, it IS out-of-round!)
What makes a separated tire unique is that the separation grows - and so does the vibration. So a separated tire will start off with a small vibration and over the course of several hundred miles grow more detectable. If you have a vibration that fits that description, get it inspected IMMEDIATELY! TODAY! If the tread comes off, very bad things can happen!
Rubbing a GLOVED hand over the tread surface is a good way to see if you have a separated tire. You are looking for a bulge!
And lastly, tire separations are largely driven by heat. So most tire separations occur in the August, September, October time fame. Hardly any occur in December, January, and February.
The most prevalent type of separation is a belt-leaving-belt separation, commonly called a "Tread Separation" and what I described above. applies to that kind. There are other types of separations, but they are uncommon, but they do have different symptoms.
So I think it very unlikely that the OP has a separation. Since the vibration appears when accelerating, a CV joint is much more likely.
