How to use global picklist value in vf?

It doesn't look like it's possible to access global picklists in Apex/Visualforce right now. At least, not the same way that you'd access a fieldset or a (Hierarchy) Custom Setting.

The best information I was able to find on this was through the chatter group on the success community for the global/restricted picklist feature. Specifically, this single post in the group's discussion.

For the time being, it looks like the only way to reference global picklist values in Visualforce would be to create a custom field that uses your global picklist, and then reference that field in your Visualforce page.

It's also good to keep in mind that global picklists are still in an 'open pilot'. Until the open beta begins (looks to be currently planned for Summer '16/ API v37), you'll need to have support activate the feature in production orgs if you want to use (in production) what you're working on.