I have both of these items in my bag right now. They show as soulbound and "Not Collected". I have equiped the items many times, restarted the game etc. But it still shows them as Not Collected. The items are listed under "Events - Brawl'gar Arena - Vendor.

Have you tried to Shift+Right Click the "ALL THE THINGS" Header? That forces a recheck of your wardrobe as sometimes Blizzard doesn't send out the flag saying "OK you learned this now"

Also, do they have a 2 hour timer on them or anything? This also prevents things as being "collected".

Damn. I feel so stupid now. Yupper. The shift right click worked. Thanks so much.

No problem! Glad that worked. Ideally it should flag correctly, but if Blizzard delays the flag then some addons can't pick up on it.