It depends on the individual fish as far as eating neons goes. I put 40 neons into my 100g community tank with large discus and most of the discus went after them and got a couple at first. One of the discus in particular liked to chase them but he gave up after the 3rd day of them in the tank. They did snag quite a few of them eventually but lost interest after a short period of time. Must be they don't taste that great.
Also, I had 15 angels that I grew out in a 29g tank. I sold some of them and I transferred the rest over to my 100g community tank with the neons still in there. They have not once ever displayed any interest in eating the neons and several of the angels have a body size large than the perimeter around a baseball. They did grow up with 5 brilliant rasboras in the same tank and eventually they grew larger than the rasboras. I think growing up with the fish has a good chance of success at keeping the two together when one gets much larger than the other.
Don't get me wrong though, angels will go after neons if they see them as a food source. The key is to make it so they aren't viewed as food.