as far as i know, this not currently possible in iNaturalist, although it has been discussed, and there is a feature request for this: https://forum.inaturalist.org/t/add-additional-names-to-the-same-place/5480.
as far as I can tell, the link to Wikipedia is based on a “text search”, but it’s based on the display name of the place, rather than the name of the place. it’s possible that adding a record for “Garnuddens naturreservat” in English Wikipedia and redirecting it to the English “Garnudden Nature Reserve” article might establish the link in iNaturalist when viewed in English, with the caveat that there may be quirks like what’s noted here: https://forum.inaturalist.org/t/wikipedia-content-not-recognized-by-inat-place/9997.