Everything that I have read, around here, about the .1 uf decoupling cap on the595 says that it should be as near to the + as possible. Whenever I use 595s I have jumpers from the -(8) to OE(13) and from +(16) to CLR(10), so there are a few places you could place the cap, and im not really sure how much it matters if you are soldering the cap directly to the chip.
This is my current 595/cap setup.
The first ones I soldered up were from pins 10 to 13, but then I figured out that 13 to 16 was a little closer, even if it was a little more difficult to place.