BERNARDA ALBA is actually the play by Lorca which translates to English best, because it's the play where he aims the most at realism (his subtitle for the play is "A Photographic Documentary"). His other plays tend to incorporate much more explicit poetry, which complicates questions of translation (as in BLOOD WEDDING). That said, though, there's always a loss in translation; inevitably, there are times when the translator has to use several words even to approximate the exact shade of meaning in one word of the original. And of course the rhythms of the Spanish dialogue just can't transfer over to English; the syntax of the two languages is too different.
Nevertheless, it does work in English. I'd recommend the film made back in the 1980s, based on a London production, with Glenda Jackson as Bernarda and Joan Plowright as Poncia.
"Sweet summer evenings, hot wine and bread /
Sharing your supper, sharing your bed /
Simple joys have a simple voice:
It says why not go ahead?"