Used a ton of wings on my Poke'mon(this happened to my friend too) and its base stats didn't rise like the game said they would. My suspicion is that they raise EVs, but I'm not sure.
They add 1 EV on,every four you get a stat increase.
it is because 4 evs make 1 stat points at lv 100
so maybe you didn't give enough wings or your Pokemon's level is quite low