It is open to the Stream. The Workshops are an integral part of Neopoet.
You are just asked to read the syllabus of the workshop to understand the context.

Some workshops specifically ask members to ignore content to learn technique, others ask them to post rough drafts to show development.

It is not writ large on the page, so you could miss it, but if you see a poem is a workshop poem, please read the syllabus before commenting. Feedback from the participants is usually highlighted in blue box, that's another sign you may have missed that it is a workshop poem.

We're all in this together. I have seen many learn from workshops they have not participated in, but you learn more from doing it!