I agree, but Vesicularia montagnei is apparently not recorded from Hawaii. Apart from that, it seems that also species others than montagnei float around as "Xmas moss".
Here a moss checklist of Hawaii: http://hbs.bishopmuseum.org/pdf/trop-bryo.pdf
=> The known Vesicularia species from Hawaii are V. inflectens, V. perviridis and V. graminicolor. At least these names are unknown to the hobby, but who knows if these species are already spread incognito as aquarium mosses.
But I'm not sure if the Haleiwa moss is a Vesicularia at all.