Recently the Bottles team announced they've been granted funding by NLnet NGI Zero Commons and now they've given more detail on what it means.
In the new post they clarify they haven't actually received anything yet as it now goes through a planning stage to define what budget they will be given and how it will be spent. Additionally, this funding is for Bottles Next, their total rework of the app and not for maintenance on the current Bottles app.
With that in mind the developers mention it "doesn't mean Bottles is financially secure", as the current existing Bottles app is still funded purely by donations. And, once Bottles Next is available, it will too "live on donations from the community" as while the funding they will eventually get from NLnet "is a huge support" it's finite.
Since the news of the funding broke they said they've "seen donations decline, especially recurring ones" which is a shame and note that "The funds don’t cover servers, maintenance, or running costs. And without direct support, the risk is that Bottles will be overshadowed before Next is ready".
They also said they're working on a fresh update on the progress of Bottles Next and how development is going.