Do workshop publications hold the same value as conference publications in CS?
No, workshops are generally (at least in my area of CS) of much lower value than full conference proceedings. (Especially when held before a more major conference.) Even though workshop proceedings are published, they are not always considered archival, and usually are stepping stones to full publications later on. A workshop is a good place to get feedback on ideas that can then be upgraded to a "full" publication in the future.

But, I'd strongly advise you to attend the workshop in order to meet and interact with people in the area! You can get great feedback for taking a weak conference submission and making it a strong accept.