Time Machine backup to an SMB share Mavericks
Pulled this from MacRumors:


After you get the sparse bundle created in your desired location, mount the sparse bundle by double clicking it.  It should mount just as any other drive or image file will.
Once that is done open up terminal and run this command (leave the quotes in place):

sudo tmutil setdestination "/Volumes/Time Machine Backups/"

Now open up Time Machine and turn it on.  You don't have to select your disk, the command in terminal did that for you.