According to http://blog.stackoverflow.com/2010/07/new-per-site-metas/ and How does the reputation on parent and on meta site work?
Reputation is always inherited from the parent site.
However it is not obvious from the meta site UI.
It causes people's confusion, e.g. see
Upvoted question having no effect on rep in Code-Review meta
How does reputation between the main site and its meta work on SE 2.0?
It was strange for me to see that someone has a big reputation on meta site, when he has only one or two questions/answers and it took me time to find the reason.
It will be good to improve UI on meta sites
Change tooltip on user info from "Reputation score" to "Reputation score on parent site"
On user profile page change "Reputation" to "Reputation(on parent site)". It may be required to change position of badges on profile page to highlight that that badges are earned separately on the meta site.