you are right, it was my mistake. in fact the infinitive ללבוש is pronounced with a B, and so is the future form, while the present and past forms with a sound closer to the english v, it's just that those who transliterate like me from native sefardit usually dont make the distinction, while those who transliterate from anglit actually do
look, this debate is going the wrong way. i readily admit you are the Ivrit linguistics expert, and in my original reply to Ula232344 I accepted לובשים is pronounced as a V despite the fact the infinitive Leelbosh is supposed to be pronounced as a B. That alone is weird and confusing, but that's not the point. The point is there is a pronunciation distinction in modern Hebrew and many other languages between B and V, and in this i think we agree.
but when it comes to ספרדית, letters like B+V, S+Z, C+K+Q, Y+LL are pronounced the same in many countries. There have been respected intellectuals in the Americas, including Nobel laureates, who have proposed the elimination of either B or V from the alphabet, because in real life there's no practical reason to keep both.
if you wish to research this argument, you could start with the interesting essay "La Real Academia Española tiene mala ortografia" http://lrc.salemstate.edu/aske/courses/readings/La_Real_Academia_Espanola_tiene_mala_ortografia_Por_Roberto_Hernandez_Montoya.htm
Ok, I suspected this might have something to do with it. I completely agree that in Spanish, b and v have converged to a single pronunciation: /b/ at the start of an utterance and after certain consonants (n, l etc.), and /β/ in other contexts. "Sephardic" Hebrew still differentiates between /v/ and /b/, and doesn't have /β/, so only Spanish-influenced Hebrew (Hebrew spoken by a native Spanish speaker) will have a convergence of pronunciations.
Also, the rules are not really "weird and confusing". Any sound at the start of a syllable is dagush (plosive: b, p, k) and any sound at the end of a syllable is rafe (fricative: v, f, kh). There are some exceptions, but mostly this is the way it works.