I know that Bonvenon! is the equivalent of You're welcome/Willkommen/Välkommen.
Does bonvena describe the person who is visiting, or the ones who are being visited or, alternatively, the place which is visited?
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Keep in mind that bonvena is simply an adjective, which describes the noun it affects. Vortaro has this example:
EO: Ĝi estas al li tre bonvena
EN: It's very welcome to him
In this case, it is the pronoun ĝi ('it') that is welcome, and it is welcome in the eyes of li ('him').
It shows another example:
EO: Estu ĉe mi bonvena gasto!
EN: Be with me a welcome guest!
Here the adjective describes the person that the imperative is aimed at. The person being spoken to is being instructed to be a welcome guest.
In English we use welcomed to mean "greeted warmly", but in Esperanto, the veni in bonveni retains its centrality in the meaning.
Bon- is a pseudo-prefix which appears in words like bonanonci ("announce good news"), bonaspekta ("nice-looking"), bondeziroj ("good wishes"), bonefiko ("good effect"), bonfari ("do good"), bongusta ("tasty"), bonhava ("well-to-do"), bonhumora ("in good humour"), bonkonduta ("well-behaved"), bonkora ("good-hearted"), bonmaniera ("well-mannered"), bonteni ("keep in good order"), bonspeca ("of the best kind"), bonstata ("in good shape"), bontrovo ("sagacity, ingenuity, personal judgment"), bonvoli ("be so good as to"), bonvivi ("live well"). The commonality is that the modified concept takes its ideal, best possible form.
Thus, a veno is a coming, and a bonveno is the ideal kind—almost always because you are cordially greeted. Mi deziras al vi bonvenon means essentially "I wish your arrival to be of the best possible kind." The person who is enjoying their arrival is bonven(ant)a, and if you are making sure that their arrival is pleasant, you are bonvenig(ant)a. A warm welcome is an elkora bonvenigo.
Sometimes in English we might call a landmark "a welcome sight" even though the thing referred to is immobile and we are the ones arriving. The idea is that the new scene is "arriving" on the stage of our perceptions. For that reason I think bonvena would be okay for that, but you could also use bonveneca.