This isn't actually a Spring thing. What you are asking about relates to the Java Persistence Architecture (JPA). Which is well-supported by Spring Data, but there's nothing specific to Spring Data here.
So I'm listing this post in our ORM forum where more experts on JPA can see it.
As far as it goes, I think that your mapping to Customer Address looks suspect, but I'm preoccupied at the moment.
Loudly announcing something is true and finding out you're wrong makes you feel foolish.
Finding out you're wrong and refusing to admit it makes you LOOK foolish.