Leona definitely takes more skill than Annie.
I feel like the problem is her e is too hard to land. If you are a squishy champ (Sona) and in lane against a Blitzcrank or a Thresh you have to dodge their hooks, but that is very possible with minions and requires a great player to judge the minion wave right to land a hook. Leona's e is simply far too easy to land. Blocking the e with someone like Janna is basically impossible unless you're godly, and I've given up trying to lane against Leona as anyone other than Thresh. The problem then being that Leona tends to be better in late game teamfights than Thresh unless you're strictly trying to kite the enemy team.
Also please no Vi nerfs, I've only just started playing her and she's really fun