Hmm... Not really sure what all you are asking. Geomorphology is the study of landforms. Structural geology is the study of structures (folds, faults, etc) within the rocks at scales varying from microscopic to continental. Now of course they are interrelated. Essentially, landforms are the product of erosive processes on the existing structure of the rocks involved and cannot be understood or explained without a good understanding of the geologic structure of the rocks. A geologist trying to decipher the structural geology of a region begins by studying the clues in the landforms. All is related. Now, there is a tendency of some geographers to think that geomorphology is a subdivision of geography and try to explain landforms without a thorough understanding of the structure, petrology, and stratigraphy on which the surface landforms develop. Landforms cannot be understood without knowledge of the geology on which they are formed.
Now, after all that, both articles are in need of improvement - as are most Wiki articles. So - someday someone will work 'em over (hopefully for improvement) and maybe I will (just don't hold your breath -)
I don't really see the need for a category link from one category to the other as you have done - if we follow that to its logical end all categories would have to have links to all others as they are all inter-related. And that is an absurd proposition. Both are subcategories of Category:Geology aren't they?
Rambled enough for now.