YES eBay is a mess, they keep changing things on the site, and they are making it harder and harder to sell AND find items on the site.
BUT, that said, I have no problem finding anything I am interested in. You just have to type in relevant keywords on the search page. Depending on what kind of bottles you are looking for...... Try to think of keywords that describe bottles you are interested in and that you think that sellers most likely used in their listing headings or in the description.
For an example, I typed in: bottle (antique,old) (soda,mineral water) (green,aqua) glass (in the Collectible Bottles category), and came up with these results: (I did not check "description" or the results would be too numerous).
Another example............. looking for bottles with "PONTIL" or "PONTILED" in the heading: (but I know there will be some that are not really pontiled if the seller doesn't understand what a real pontil is)
I have basically left FeeBay. Haven't looked at it since March of this year. Still finding great bottles and haven't missed their Big Brother nonsense yet. I wish they would spin off the collectibles segments of the site and create a new venue for that. They still have a massive following, but the red tape grows larger every passing month.