Sync iPhone photo albums to iCloud web?
I forced the album to appear by doing this:


Take a new photo on the iPhone
Add newly taken photo to album on iPhone
Reload the iCloud Photos web interface


The new photo and the album now appear. 

My theory is that when iCloud recognized the new photo (which happens fairly reliably… for me, anyway) it looked at its other attributes, noticed it's part of an album, noticed that the album doesn't exist on the web yet… and initiated a full sync.

What a total kludge of solution. Seems to work though.