What are the Eris bounties? It might just be me, but I haven’t seen them when I talk to her. Are they the ones with the Taken King Symbol? Where you have to do stuff on the Drednaught?

You get them by doing a court of oryx encounter of any tier. The first one will be something like "farm 10 wormspore" or "melee 15 taken on the Dreadnaught". Once you complete that, you get another one, usually "kill 10 Hive/taken/cabal majors on the Dreadnaught without dying" or "get 10k experience on the Dreadnaught without dying" or, my personal favorite, "kill 3 cursed thralls with melees on the dreadnaught without dying" After that, the third one is "complete a (blank) rune encounter in under 2 minutes". The bounties are available once a week, per character, after reset.