Do you know the sex of the angelfish? If they are a mated pair, all may be well. But if not, you may be in for trouble as they mature. Angelfish should always be in a group of no less than four, though five is better, except for a mated pair. Kept as two or three when two or three are male almost always results in bullying leading to death of the subordinate fish. I have heard that females can do this too. Having a group spreads out this natural behaviour and the fish usually (should) form their pecking order and be fine. The more angels, the better this succeeds.
Again, not knowing the size of the angelfish now, it is difficult to say if the neons will survive or be eaten. Linear fish are frequently targetted by angels as food once the angels are large enough. It is a natural instinct.
Angels being sedate fish, as are neons, you do not want active fish buzzing around the tank, so this eliminates barbs and danios. Rasbora and characins are better tankmates, though not all of them obviously. Substrate fish are generally fine.
Byron.