Does a bipod have an advantage over a rest?

Not sure it matters much. Wouldn't shooting with your gun on a rest influence harmonics as well?

I have always used a front rest in lieu of a bipod in all disciplines of shooting bench rest or F-Class whether it be small bore. long range high power or airgun. Gives a lot more stability from shot to shot and easily adjustable. Especially the joy stick models. Key is to use a "quality" front rest and rear bag. such as SEB, Farley, Sinclair etc.Old saying " You get what you pay for" Don't skimp on your equipment if you are serious about being competitive.

As long as you shoot the same all the time then it's fine. Do you need it long winded instead? Yo!

If you are talking about shooting "competitive" benchrest where you are shooting at multiple targets with a time constraint, a good rest is much better. Moving from target to target with a bi-pod is much more "fiddly" and takes too much time. If you are shooting for groups in the back yard, it doesn't make much difference. 

I go in between a bipod and bag rest. If I'm taking a prone shot I'll use my bipod or if I have a surface when I can load it easily. I find bags better for bench shooting and shooting off a barricade or surface where I couldn't load my bipod. That said, if you can shoot off a bench well enough with a bipod to consider your results reliable, then the bipod will suffice. Practice in whichever position and with whatever gear minimizes error for you.

It works better if you need different ergonomics. Whatever is comfortable for you is best

Also depends on the bipod stability. Some are wobbly, have poor foot support or can induce cant. A front rest allows more stability and adjustment in cant and position, I find. It is a question of what suits you, but I feel a rest is just more reliable.

Now it might be just me, but I've found over time that I prefer a rest of some sort for shorter rifles and a bipod works well for longer and heavier platforms. 

I've had good results using a Sinclair F-Class bipod. I used to use a Randolf rest, but this bipod seems to work well. I must say, however, when shooting USABR 25 bull targets, it takes more time to set up with the next bull using the bipod. Accuracy wise, it's good. I've also had good luck with sandbags too. The heavy Bullsbag works quite well.