Zebras are wild animals and should be left as such. You cannot fully tame a wild animal.
I know a little of what I am talking about, my grandfather owned a gamepark in Zimbabwe and I have had experience rearing orphaned wildlife, we had a lion for about 3 years living with us until he went back to the park. Actually we had several and you just had to be very careful incase there natural instinct surfaced - which it invariably did.
My uncle often got the orphaned zebras and impala to rear, all were bottlefed and I know the zebra was a wild one who was really really happy to return to the wild.
I was always told as a child that you will kill a zebra if you rode one. I am sure that to a prey animal something jumping on their back is heart attack material and their very instinct will tell them to run. I feel very sorry for them when I see pics of zebras being ridden.
I guess like our horses they could probably adapt to being ridden, but with a zebra, unlike our horses who gracefully (sometimes) allow us to ride them, do not have years and years of domestication to dull some of the wild instincts.
Our domesticated horse has taken millenia to be domesticated and look at places like Aus (brumbies) USA (mustangs) Namibia (the desert horses) how quickly they adapt back to being wild.
So if I had to opportunity to buy a zebra I would give it a huge paddock with a couple of herd companions and let it be free