Where the hell is dreamwalk?

[Rufflebottom-bloodhoof (Rufflebottom)]

Someone else has posted about this in Bug Reports with the same work-around that I mentioned.

New Druids don't receive Dreamwalk

You can physically run to the Dreamgrove, you’re not required to use the portal–It is in Val’sharah. It’s a pain to do it every time you need to go back to your order hall, but that is probably the only solution at the moment until they look into this. Either way, you will be able to progress through Legion with a little bit of extra annoyance for the time being.