Yes, my fencing is a 3-4 different types strung together (hey, we live in the woods where trees constantly are falling on the fence and I've had to do lots of repairs with whatever was available at TSC LOL!). It works just fine and still gives a mighty zap
I have no idea about the bipolar fence though
“While the rest of the species is descended from apes, redheads are descended from cats.” Mark Twain
We stick all kinds of wire, tape and rope together too. Generally it takes some years and repairs for it though.
About the bipolar - I think the material won't matter but you may have to retain the bipolar method into your new work. I don't know enough to know if the bipolar fence would short out or cause the standard fence to short out if the bipolar hot or not hot(ground) wire were hooked to an earth grounded system.
You could always experiment . . .
If Bi-polar means alternating hot and grounded fence strands...Yes you can connect different fence tape materials together. Think of it like electric wire (which it is) Hot to hot .. ground to ground wires... or not since the earth under the hoof is the ground.
I have both Horseguard 'normal' and their bi-polar electric fence tape hooked in together and works just fine! just be aware when 'testing' the bi-polar part of the fence to check on the positive side... you might think your fence is 'dead', but it isn't
Why not do the bipolar tape everywhere? We've had the horses home for just over a week now and so far it's been working great. It is HOT and the horses respect it. This is two young warmbloods who do a lot of playing and galloping near the fence.