ok, just wanted to clear up that there are contractions, my friends here use them and I am the only one here behind. I know its been years since the original post, but if there is ever  anyone interested, I found a stenography  or grade two Spanish course. Its dated 1998, and even though I am not sure if that would be the latest (its been hard to come up with something stable because Spanish is spoken in so many countries) it seems to be pretty legit and complete. of course, the entire text is in Spanish and sadly in .doc form but its totally doable as there are tables with the signs, their exact dots and what they mean. The course gives you exercises at the end of each section, and a cheat sheet with the answer to every exercise. Signs are grouped using the same logic for teaching braille to sighted, like a through j first, and then k through r, and so on. As you might expect, just like in English, there are common words linked to single letters. For example,
B for the word bien, c for the word con, k for the word al, ETC.
Other signs, are used too, probably way more than in English for single words. like the & symbol stand for ella, and a few accented letters, like ú stand for según.

the thing is that, as with any complex language like Spanish, endings are more difficult and require way more context. And so it can get really really abbreviated but its doable as well. And at last you have contractions. For example dots 2 3 6 stands for "er", dots 1 2 6 for "em" and so on.

Of course I really doubt there would be many books using abbreviated Spanish Braille (some efforts certainly had been made to revive it) but I don't think it took off as well as it did with English.