My take on this as a level 80 bard with a bit over 1200 aa's.
Bard power scales with the number of people in a group. That said, a bard is a MUCH more efficient leveler when playing solo if you goal is to level fast.
1-50 you can go toe to to with most mobs in a duo but we don't tank well. Remember tanking is the ability to take a hit and hold agro. We have few agro abilities beyond our meager DPS. Best agro combination I can think of is snare/slow, dot and mezz. 50+ this will be very noticeable as a slow/heal coming too early means dead healer.
In spite of wearing plate, we don't take hits well, so unless you are overgeared for the content there will be significant downtime.
If you master the ability to charm and dot(swarm kiting), you can level/aa insanely fast and all you need is a decent drum.
If I had to do it over again, i'd go with a cleric/bard duo upto about 55 so as to learn how to do all the bard things to need to do, pull, mezz snare, charm, dot, etc. At that point I would solo using swarm kiting with my /lfg up.
Good luck with your Bard! I love mine and wouldn't play another class.