That's a great looking image. I'm always amazed at the quality of good pinhole exposures onto medium format film.
The forested trees in the foreground appear a bit dark, which is okay actually, but perhaps you might want a bit more detail present; this may have more to do with your metering method than reciprocity failure. You may want to try pointing your light meter at the trees and keep from getting too much sky exposure on the meter. I've come to do this when exposing paper negatives, since the sky gets blown out (i.e. over-exposed) using paper, I'm not interested in capturing detail in the sky, but rather the landscape itself, so I try and meter the foreground itself.
I look forward to seeing more results; great job.