Can I use winter spring tiger mount on horde?

If I donate for winter spring frost saber it says it's for alliance but it will let me donate for it with my horde toon, I just want to make sure I'll be able to use it on horde and not buy it for no reason

You shouldn't be able to learn it, as it's Alliance restricted.
Just like Alliance can't learn Horn of the Frostwolf Howler, as it's Horde restricted.

The only way you can get a few mounts like that is by transferring from alliance to horde or vice versa. Almost all mounts convert though, so it's not likely you'll be able to use it. However, I have seen horde friends with the Stormpike Charger from the vote shop without transferring, but personally I wouldn't risk it.

I don't know if I'm going crazy, but I can't find that mount in the coin shop.