Bloke and dog finally wander in vegetation (8)
I believe the answer is:
mangrove
'vegetation' is the definition.
'bloke and dog finally wander' is the wordplay.
'bloke' becomes 'man' (I've seen this before).
'and' is a charade indicator (letters next to each other).
'finally' indicates one should take the final letters.
'wander' becomes 'rove' (synonyms).
The last letter of 'dog' is 'g'.
'man'+'g'+'rove'='MANGROVE'
'in' acts as a link.
(Other definitions for mangrove that I've seen before include "Coastal swamp plant" , "that grows in swamps" , "Tree of coastal swamps" , "Strange tree of tropical swamps is a veg, Norma" , "Plant growing in swamps" .)