Will a wildcard CNAME take precedence over a named CNAME record?
Solution 1:
In BIND, the wildcard matches when another record does not exist. See http://en.wikipedia.org/wiki/Wildcard_DNS_record.
Solution 2:
A more specific entry always overrides a wildcard, not the other way around.
For chapter and verse, see §4.3.3 of RFC 1034.