Can't re-partition my bootcamp volume.

Click on 251GB APPLE SSD SM0256F.

After that, click on the Partition tab.

Then, click on the '04' partition and press the '-' button on the lower left. Apply changes.

Then, drag the bottom slider of the first partition all the way to the bottom to recover space.

To modify partitions, you must select the drive itself and not its underlying partitions.

 

I've come to a conclusion that disk utility is pretty ****** as it will hide recovery partitions and complain a lot. Your friend is gdisk either from here:
http://sourceforge.net/projects/gpt...1.0.0/gdisk-binaries/gdisk-1.0.0.pkg/download
or within a linux distribution e.g Ubuntu or Clonzilla (which is based on Ubuntu) WARNING - gdisk is powerfull utility and MAY WIPE your partition table if you are not carefull about what you're doing. RTFM!
On how to use it just google: gdisk bootcamp
For starters check this out:
https://discussions.apple.com/thread/4144252

To sumarize you must delete the recovery partition and the empty
bootcamp partition (via gdisk) and then you can expand the MAC volume to full capacity. (via disk utility)

Don't wory about the recovery partition it will be created automatically after OS X upgrades. Or better yet just create a bootable Yosemit installer. (Plenty of tutorials out there)