I think it’s a good take on the prompt and a very interesting city. The poem is just a nice free form poem that’s one stanza without a rhyme scheme.
One thing I wanted to point out, and someone else hinted on it, is that the descriptions and city overall are left very vague. This isn’t necessarily bad, but it depends on what you were trying to do.
Every description leaves some things vague, it’s impossible to cover every little detail, and the readers will “fill in the blanks” when things are vague. However, you as the author lose control of whatever that feature is because everyone can imagine something different.
My advise would be to pick the most important features (someone mentioned what the vines look like and how they work, but you could pick anything like the size of the city, if people try to escape and can’t, if people are aware of the effect the vines have on them, or literally anything important) and describe those important things in more detail so we imagine YOUR city that YOU want us to see.
Let us know what specifically your vision is. Unless of course the goal was to create a concept and let the readers imaginations run wild… Anyway, keep up the great work.