Right now in Colorado you can withdrawal your welfare money at pot shops. I say "right now" because I'm sure the government will put a stop to that in due time. They've stopped people in Michigan from being able to withdrawal money from casinos and strip clubs. I'm not putting marijuana shops in that category but it seems like they will put a stop to it, eventually.
However, the GOP did lose a vote to the Colorado Senate Committee 3-2 on the vote to add pot shops to the ban list. It's not like it would be this huge deal if they did add it to the ban list. There are so many gas stations, grocery stores and other place where there are ATMs. You'll just have to stop at the gas station to get your blunt wraps and money to buy your weed before going to the legal pot shop.
No matter what they do, they aren't going to stop you from getting your pot!