There’s no “up” involved in fino. It means “until” (or “finally”, if it helps to see the common root).
Salire has multiple meanings; “to go up” being one of them (I’m more used to it meaning “to go out”). But you can salire (up or out) indefinitely. Fino is what gives the limit, so no, not redundant.
They’re both correct. The difference is one of emphasis.
. . . va fino a undici — goes as far as eleven
. . . salofino a undici — goes up as far as eleven
Fino doesn’t necessarily mean “up to”. Vado fino a Roma; I’m going as far as Rome, but the journey from where I am now towards Rome might well be downhill, or level.
So, va fino a undici doesn’t imply that 11 is the upper limit of whatever it is you’re talking about; you might use a phrase like this when talking about e.g. how low the temperature might go tonight. But if you use salire then you’re definitely talking about an upper limit, and any movement towards that limit will be an ascent, not a descent.