If I neeed a decongestant for short term use, I take one and keep an eye on my BP and adjust meds if necessary. I will use cheap, generic pseudoephidrine.
For long term allergies, a more stable solution would have to be found.
With a blocked ear I would DEFINITELY take the decongestant because a blocked ear can quickly become a much more dangerous situation than slightly raised BP.
(Take some steamy showers; they hasten the opening of a middle ear.)