It's ironic, in the Smiley sense, one of those on the bottle is finished producing families of woodpeckers? (8)

'woodpeckers?' is the definition.
(wryneck is a kind of woodpecker)

'it's ironic in the' is the wordplay.
'it's ironic' becomes 'wry' ('wry' can be a synonym of 'ironic').
'in the' becomes 'necks' (I can't explain this - if you can you should believe this answer much more).
'wry'+'necks'='WRYNECKS'

'smiley sense one of those on the bottle is finished producing families of' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.

Can you help me to learn more?