Not that I can see. The only leak would be if SDL requires you to free the screen data or the pointer after you use it, or if that function somehow internally increases the reference count for the object.
As long as you don't use ptrBuffer to delete the object, you will be ok. But ptrBuffer does not cause a memory leak in this case.
WORD *Buffer=new WORD;
WORD *Buffer2=new WORD;
delete  Buffer;
delete  Buffer2;
I pass an IDirect3DDevice9 interface pointer around in my engine and as long as each class understands that they can use the pointer, but they cannot release it or delete it, everything works just fine.
The danger is that any object could mistakenly delete or release the pointer in which case the whole system comes crashing down.