I think it indicates more about personality and coding style than direct experience level.
Good naming conventions may indicate experience, a good mentor or simply a methodical person. I have also seen fairly chaotic code come from highly-experienced people who were in a rush or simply a fast-and-loose programmer. The code will probably indicate whether someone's a stable or volatile.
Conventions may indirectly demonstrate experience levels though, since the conventions someone uses can hint at the era and language they first learned to code.