Re: travel and BPPV
Due to the relief of symptoms after the Epley, BPPV is present. There is no harm in staying on the antivert medication when you have BPPV. But quit it once the BPPV is cleared because it will hinder your body from compensating for any vestibular damage.
The ear pressure issues do not play any role in BPPV (you probably know that, but I will say it just in case).
Balance problems caused by pressure changes fall into the diagnoses of meneires disease, mav, perilymph fistula, or superior canal dissonance. If pressure changes make you dizzy, then it is possible that you have one of these conditions, possibly in addition to BPPV.
Good luck and keep us updated.