Endless red wine to declare (6)
I believe the answer is:
report
'declare' is the definition.
(thesaurus)
'endless red wine' is the wordplay.
'endless' means to remove the last letter.
'wine' becomes 'port' (port is a kind of wine).
'red' with its last letter removed is 're'.
're'+'port'='REPORT'
'to' is the link.
(Other definitions for report that I've seen before include "Sharp noise; rumour" , "Formal document" , "Inform about the sound of thegun" , "A crack" , "Noise - information" .)