apartment search sites failing

Long term rentals are those of at least 12 months. Difficult to know why you are getting the result you report. I just took a quick look on Se Loger and found about 700, 2 bedroom apartments available in Bordeaux.

You might also check here:

http://www.pap.fr/
http://www.logic-immo.com/

While I don't want to assume, it does sound a bit like some sort of cockpit error that
OP hasn't been able to diagnose.

I would also think that for a search like this, you might be better off finding an agent
in the area who can advise on all of the aspects of a long term rental (unless you
know this type of stuff already). I wouldn't execute a long-term rental agreement
in a foreign country without some sort of representation.

Maybe then it's an anomaly of going to these sites so far only on my phone. I'll try later with my PC. Merci for the extra links, I'l lcheck them out.

Shoeflyer, yes, do you know the ACRONYM "PEBKAC"? Problem Exists Between Keyboard And Chair.
OTOH, maybe it's partly my phone UI. I'll try today with my PC. Also, mais oui I'll get an agent when I approach the time to visit, a year from now. Presently I'm just trying to get a sense of what's available and then to show my wife to spark her interest.

OP, makes sense on both counts. You didn't say when you were planning to go, and there
is a large diversity of experience on the site, so I try to not assume naivety or experience.

The webpages for mobile browsers are not the same as for desktop/laptop browsers.
Not out of the question that there are differences in functionality, placement of pulldowns,
options, etc.

We found it very difficult to find a long term apartment in Bordeaux through seloger and similar sites. Not sure what you mean by "long term," but AirBnB is still good for a month or two. For longer stays I'd check into Bordeaux Autrement as we did, though they're a bit spendy.

Most Bordelais find apartment rentals through the local immobiliers (there are many) or through Particulier à Particulier (pap.fr), but they require pre-qualification. PAP basically exists to pair landlords and tenants without intermediaries. Personally, I wouldn't be comfortable going that route.

Long term is undefined. If it’s under a year, you need short term rental agencies for visitors. Just google vacation apartments. A brick and mortar agency with people who inspect the apartments is preferable.
One year, you can sign a furnished rental contract, unfurnished is a three year contract. For the 1 year or more, you need to put together a rental dossier containing proof of funds, salaries preferred over pensions and investments, a guarantor if you can’t show a salary no matter how much you have in your IRAs. It works differently here. A handholder agency, such as what the other responder had, would be good for someone who needs to learn the ropes. They know owners who accept American retirees without the usual requirements. It’s very different in France. We have a law and forms to fill out for every situation you can imagine. It’s not nearly as free-flowing as the US. Landlords are very picky because evictions can take a looong time. You will find private groups on Facebook for Americans in Bordeaux, or English-speakers in Bordeaux, etc. Join them and you’ll be able to to learn and ask questions apartment agencies.

Check FeWo also. I, and several friends, have used it successfully for stays inside of a month. It's my "go to" over AirBnB and Booking.com.

There's also the "bail mobilité" that is designed for rental periods of a maximum 10 months. Some of those are listed on AirBnB, but not all of them are. They can be an excellent choice for those whose stay duration matches the restriction, if a person can find one.

Leboncoin.fr is another place one can find apartments; it's like the French version of Craigslist. You'll maybe need to scroll through lots of used cars, bicycles, tools, baby carriages etc to find an apartment, and scams are not infrequent on leboncoin. But lots of French people use it. It avoids immobilier fees.