Do Wonder Woman's bracelets have special powers?

Those Bracelets are called Bracelets of Submission in comics.

The Bracelets of Submission are a pair of metal bracelets or cuffs worn by Wonder Woman and other Amazons. They were an original creation by William Moulton Marston as an allegory for his philosophy on loving submission and the emotional control associated with it in order to balance out the strength of the human ego. These bracelets have thus far proven indestructible and able to absorb the impact of incoming attacks, allowing Wonder Woman to not only deflect automatic weapon fire, energy blasts and other projectile weaponry, but also to absorb forces from a long fall.

In comics they were powered by Aphrodite and symbol of submission to their patron goddess Aphrodite and all Amazons wear it and they are made of amazonium. They do got retcon few times but always had similar powers and had a weakness to male welded chains which got removed in later comics canon.

And as mentioned by Gallifreyan in comments, this bracelets are more to restrain her powers:

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But neither in Batman v Superman: Dawn of Justice nor in Wonder Woman any of it got explored, we just know that Wonder Woman have them from childhood in Themyscira. So those bracelets seems like a gift of Gods with special power of absorption and reflection of energy/attacks as seen in the films.

Note: Previously I forgot that she had that from childhood, credit goes to competing answer of T.E.D. .

Note that in the movie, unlike all the other artifacts, the bracelets she had on when she was sparring the other Amazons, and she even had on at age 8.

Now we know from the comics that her powers have gone through multiple revisions. The "classic" Wonder Woman that I grew up with couldn't fly, and her bracelets did nothing much other than deflect bullets. The most recent DC comics version has the powers of a god (including flight), and her bracelets are actually there to tone down her powers so she doesn't accidentally hurt everyone around her.

Given that we've seen from the movie that she can fly, and that her bracelets do more than just deflect bullets, I think its probably fair to say that they seem to be steering her more toward the modern interpretation. So its quite likely they serve to tamp down her god-like powers (as the other answer also said).

They (and by "they" I mean screenwriter Alan Heinberg, who also created the Young Avengers comic series for Marvel), were hiding those bracelets in plain sight the entire movie. It seems likely there will be a pay-off for this in the future.

The animated Wonder Woman video from 2009 movie establishes the origin of her bracelets (gauntlets?) as the shards of Zeus's former shield. This would explain why in the 2017 movie [spoilers below]

at the end of the movie, when Ares fires a lighting bolt at Diana and she instinctively blocks it with her bracelets, rather than deflect the energy, her bracelets seem to absorb it. This makes her curious, as the lighting seems to conduct between the bracelets.

This would prove to be an interesting way for Zeus to provide a way to protect his "daughter" even though he couldn't be there.