I have almost 50 ranked games with Bard with a 50% winrate. He seems "okish" to me, at least with a good team.
I think he needs more power in lane. Apart from a triple healing shrine, there isn't much to do during lane. Q has a short range and slow speed so it's easy to dodge and the way minions position makes it even harder to get a stun.
But he is very good during ganks imo.
I'd just change his Q a little bit. Maybe make it so it can hit 2 minions and a champ to stun all 3 of them, but still keep it at 2, if it hits 2 champs. This would give him some pressure in lane and actually make the enemy move around and not just stand behind those 3 caster minions, that always stick together, so you can never stun them.
Also I'd change his Q so you can use it on people you ulted, while they're still under the effect of your ult. This of course wouldn't be optimal. Your Q stun lasts for 1.75 seconds at max rank I think and your ult lasts for 2.5 seconds. So if you use your Q straight away, you would just throw it away. But if you used your Q 2 seconds in your ult you would have still have 1.25 second stun. I'd mainly make it this way, to counter ulted enemies spamming their flash/escape ability, so they can escape almost the same moment your ult ends, while you actually have to time your Q and take into account it's travel time as well.