Leveling skills past that point does not roll over the attribute bonus to the next level. By leveling the skills associated with a specific attribute you gain bonus points to that attribute (maximum 5 for a combined skill increase of 10). In addition every attribute besides luck has three skills associated with it.
You can continue to do this even if you can already level up so you may be able to level up multiple times by sleep over and over. An example of what I mean by raising your major skills by a combined amount of 10 would be: I haven't played Skyrim so I don't know if it is different but in Oblivion, you level up by raising you major skills by a combined amount of 10 and then sleeping.
