Most likely.
A friend of mine wanted to put neons together with her betta, so I experimented with two of my bettas to see how they'd react to the neons.
My female immediately chased them and tried to kill them.
My male swam around the tank for a bit, and the second he noticed a shiny neon, he went right after it and tried to eat it.
I'd say it's a bad idea. Not so much that they'll see a neon as competition, but as food.