Where can I find poles for this REI tent?

Did you bring it with you when you went to REI or did you just ask? Their tent equipment is generally fairly interchangeable, there's a good chance something for a newer one could be made to work. I have one from roughly that time frame (I don't have it handy to check the date, unfortunately, it may be a few years newer) and it looks really similar to the current models.

How many poles did you get? I think REI's 1/4 and 1/2 dome tents have a sort of hub design, so that the pole should really only come in one piece that looks sort of spider-y, with 4 poles radiating from the central hub. If you have more than one multi-armed pole, maybe the non-grommet ends need to be connected to the hub and it was disassembled for shipping? Later model REI tents have a slightly different pole configuration - instead of the poles meeting at the hub and forming an 'X' like they did in earlier models, they come in sort of offset, so there are two hubs and one segment kind of sticks out in the air to hold up the side walls of the tent and make the walls more vertical than they were with the X configuration. Even if you've got the hubs correct and everything and you're just missing the grommet end of the pole, I think that's really just an insert that goes into the end of the pole, so maybe you can check with Tent Pole Technologies, tell them you're missing the grommetted end thing, and ask for them to supply it to you, assuming that inserting it is something you can do yourself. Attaching the poles to the tent via hooks or sleeves shouldn't make a difference. I have a (non-REI) tent that has three poles, two of which are sleeved and the other one clipped, and the poles are totally interchangeable - there isn't a pole that specifically needs to be the clipped one.

REI ought to be able to tell you who was the vendor for that tent, or maybe there's a label or inspector's tag somewhere that will give you a clue. Then find the vendor. Or find a pole-set that's close but a bit too long and cut down one of each section.

REI ought to be able to tell you who was the vendor for that tent, or maybe there's a label or inspector's tag somewhere that will give you a clue. Then find the vendor. REI makes and sells the Quarter Dome tent themselves. I'm not sure what you mean by "vendor" that wouldn't apply to those functions.

Tent Pole Technologies did not send you correct poles. Your tent is designed to insert the poles either end first and then thread them into the grommets (as I'm sure you know). Unless you filled out the form incorrectly, they made a mistake, and they should make it right. That tent gets good reviews. I think it is worth leaning on TPT. Tent pole assembly is not rocket science, and they should be able to give you grommet end pieces on the poles you bought without redoing every part, even if you are the one at fault.

Your tent is designed to insert the poles either end first and then thread them into the grommets (as I'm sure you know) The grommets are typically the things on the tents that you insert the end of the poles into (some tents have pockets or some other mechanism). At the end of the pole, where it's supposed to be inserted into the grommet, there's an end piece that looks like the second thing shown http://tentpoletechnologies.com/?page_id=671 (the "locking tip"). If that's all the poles that ethidda got needs, it looks like an easy fix. For poles that are attached to the tent by clips, you need to thread the poles through anything - just insert all the ends into the grommets on the tent and start clipping the tent to the poles.