Wine is noted as a 'fragile and bulky' item on this baggage page:

http://www.delta.com/traveling_check...ulky/index.jsp

This pages notes that spirits under 48 proof are not hazardous:

http://www.delta.com/traveling_check...oods/index.jsp

This suggests, but does not absolutely affirm, that DL has no limit for checked wine. Good luck.