Quote...a pan-tonal harmonic treatment that nevertheless suggests a discernable tonal center.
Just a quick reminder from our definition of 'romantic':
Overall, though, music of the romantic era still shares recognisable attributes: the restrained employment (if at all) of dissonance, a reliance on 19th century models of harmony and construction and the fundamental importance of melody. Mere tonality, without strong elements of these other characteristics, does not qualify music as being romantic in style.(emphasis added)
We have highlighted this distinction on many occasions in the past, so we would once again plead for caution in posting concerning music which does not fit here. The mere fact that Sowerby's 5th Symphony dates from 1964 should also give one pause for thought...
As an aside: this CD of Sowerby's music suggests an attractive idiom, but certainly not a romantic one:
http://www.amazon.co.uk/dp/B003H3H9BA/ref=dm_cd_album_lnk