Wonderful enthusiast starts to tell company about wine (9)
I believe the answer is:
fantastic
'wonderful' is the definition.
(synonyms)
'enthusiast starts to tell company about wine' is the wordplay.
'enthusiast' becomes 'fan' (fan is a kind of enthusiast).
'starts to' suggests taking the first letters.
'about' means one lot of letters goes inside another.
'wine' becomes 'asti' (Italian wine).
The initial letters of 'tell company' is 'tc'.
'tc' placed around 'asti' is 'tastic'.
'fan'+'tastic'='FANTASTIC'
(Other definitions for fantastic that I've seen before include "Great!" , "Brilliant or unbelievable" , "Wicked" , "Super!" , "Weird" .)