I got a Wacom Intuos tablet and was having trouble using it for general scrolling - eg. using a web browser. Couldn't figure out how to map the lower button to scrolling, the way it is with the middle mouse button on my thinkpad.
The solution, for anyone who has the same issue, was easystroke. I'd say the solution is similiar for Bamboo and Touch Wacom tablets.
Install easystroke (I'm using Ubuntu 14.04 and it's in the repos).
Click the preferences tab and then the button labelled 'Gesture button'. In the window check 'instant gestures' and in the grey box click the lower button on your stylus pen.
Then in the actions tab add an action and choose type 'scroll'. Then click 'Record stroke' and click in the lower button on the stylus again.
Clicking in the lower button and moving the stylus should scroll now. YMMV. But if you're having trouble making your Wacom tablet work the way you want, try easystroke. You may also wish to go to the Advanced tab turn off the annoying notifications on gesture activation.