Actually the text is centered. It's the chips that are not. I can't confirm whether or not this was the case in version 2 right now, but I'll make a note to see if this has been broken.
So, the chips are left-aligned while the chip values are centered. You can't fix this completely, but you can make it a little better by changing the width attribute to a size closer to the actual width of the chip images. Of course, this will bring the chips closer together, but that's the trade-off for now I guess.