'seen all over' is correct and usable in written English.
This phrase is used to describe something that can be seen in multiple places. For example, "The trend of veganism is seen all over the world."
Handsome new houses are seen all over town.
This pattern was seen all over the country.
"It should be seen all over the world," gushed García.
The results of this fear can be seen all over the world.
The love of contrast can be seen all over the menu.
Big billboards and all sorts of aggressive promotion can be seen all over Belgrade.
It is seen all over the world on sightseeing work, often claiming descent from London.
This decorative leitmotif could be seen all over the dining room.
There's an element of the N.F.L. that brings crime, drunk driving and fights that we've seen all over the nation".
Fashion is getting back to nature, in a riot of colourful floral patterns to be seen all over the catwalks.
The effects of the glittering court of the Normans can be seen all over Puglia through their churches and castles.
