I have found

Blood fish and bone the best, as it slow to release the nutrients , which is ideal for the way they both grow.

The best Bamboo I have seen was literally grown on top of an old compost heap and drain. They really can soak up a lot of Nitrogen and water. So any high Nitrogen feed used for lawns will benefit it immensely. NZ Flax (Phormium) would appreciate the blood, fish and bone meal as GG has said.

I used Nitrogen one year and the following spring covered in aphids , never used again and never had greenfly on them again

You had greenfly on what plant? Bamboo leaves or Phormium? Never seen any pest on either apart from caterpillars on new Phormium fronds and that was on Phormium banksii and not the more common tenax. But the fact remains, Bamboo, esp the timber ones, love nutritious feed.