Blue Aprons affiliate program: Is on Impact Radius: https://www.blueapron.com/pages/affiliates

Peleton: Looks like they had a referral program, but removed it (info here: https://www.reddit.com/r/pelotoncycle/comments/71b2k1/peloton_has_banned_referral_code_sharing_and_how/)

Leesa: On Impact - https://www.leesa.com/pages/affiliates

Boll & Branch: Looks like they were on ShareASale but no longer (although Viglink signup is still there: https://www.viglink.com/merchants/53747/boll-and-branch-affiliate-program)

As you can see - there is not one central network that these types of merchants run their affiliate program through. I would decide who you want to work with and then go the route of seeking their affiliate program out. If that is too manual (i.e. if you are talking about 100's of merchants for which you don't want to signup for each) and don't mind parting with a small amount of the total offered commission - you can signup for skimlinks or viglinks and auto monetize your links that way.

Hope it helps!