Fantastic island life — yes, one would be dead blessed here! (7,6)
I believe the answer is:
elysian fields
'one would be dead blessed here' is the definition.
(blessed resting place in Greek mythology)
'fantastic island life yes' is the wordplay.
'fantastic' indicates an anagram (a fantastic or improbable ordering of the letters).
'island'+'life'+'yes'='islandlifeyes'
'islandlifeyes' anagrammed gives 'ELYSIAN FIELDS'.
(Other definitions for elysian fields that I've seen before include "(Mythological) Abode of the dead" , "state of perfect happiness" .)