Gave the leftover tea a second steep this morning for breakfast. This came out more watered down, obviously, but had a rich blueberry flavour nonetheless. The black tea taste was essentially gone (not that it was strong on the first steep) but in my opinion, it really stood up well to the second steep. The beau was proven wrong, haha!
I do agree with another poster who said that it had the flavour of the bluberry filling you would find in a good danish. Yum!