You don't. /bug and /feedback don't generally get you a direct response from anyone. /bug isn't necessarily you asking for something, but rather you lending a helping hand by pointing out a flaw. They get compiled and put in front of devs to investigate and if your issue is corrected, it'll show up in the patch notes. The only way to get direct feedback would be through the /petition ticketing interface or take a shot through the boards.
If you are stuck on a quest point because of a bug or lost something due to it, /bug it and then /petition for a resolution. A GM may be able to restore your item or respawn a mob or reset some other condition ahead of a bug fix.