Depends on the animal and it's lineage. A high quality angora rabbit will produce upwards and sometimes over 15 ounces of fiber per year. One ounce of my 10.5lb French Angora bucks wool for instance will nearly fill a gallon ziplock bag. I just harvested him two days ago and I got about 3.5 ounces off of him but remember, he is French, not English. And all of that is not useable, you have first quality, second, and then third which I don't spin or sell, I save it for adding to nestboxes.
I raise german angoras and german angora hybrids. You can get at least 15 ounces of useable fiber not incuding seconds and dirty dingleberries
Well-managed purebred germans give you over a pound per every 3-month harvest. I started with english reading that they have the finest wool.They do, but it matts terribly if you do not brush at least once a week. Also, none of my english ever had more than 4-5 ounces of useable wool. That's why I switched to Germans, they are a commercial wooler realitively new to the USA. The IAGARB club supports all breeders internationally. Typically when I spin I make 2 oz 3-ply balls of 100% angora rabbit wool, I get 120 yards. 3-ply worsted weight. Hope this helps!
I do get those amounts from my germans but it can fluctuate depending on season. We are entering winter snow time and the outside temps are around 30 degrees during the day, the rabbits really fluff up and I get heavier harvests. But shearing in winter can be harsh, I shear and then put a coat on them, and stuff their cages with straw. Even have kept them in the house for a few days on occasion when the temps fall around the single digit range. I have no more pure english, they are all hybrids. The hybrids produce 8-10 oz useable. Not bad!