George Swithenbank married Bessie Ellen Prall 1906 in Portsmouth, Hamps. There were no Swithenbank's on any of the Channel Islands Census. Indeed, all the George Swithenbank births seem to have been in Yorkshire.
However, I have found the Jersey link through the Prall family. Bessie Ellen Prall's birth was registered Dec. qtr. 1884 Bideford, Devon. Although I've found her on 1891 and 1901 Census both state she was born Horsley Down, London. Piecing it backwards it seems her father - William John C. Prall bc.1862 St. Helier, Jersey - married an Elizabeth Mary Lucas Mar.qtr. 1884 at Dorchester, Dorset. Bessie's birth registered at Bideford Dec. qtr. 1884 and in that same quarter in St. Olave, Southwark, London is the death entry of Elizabeth Mary Prall bc.1859. In June qtr. 1885 William John C. Prall marries again to a Sarah Ann Lucas bc.1866 Pertwood.Wilts. Perhaps Elizabeth Mary and Sarah Ann were related - sisters???
1901 Census Portsmouth
Annie Prall 38 b.Salisbury, Wilts.
Bessie E. Prall 16 b.Horselydown, London
Willie C. Prall 15 ditto
John Prall 8 b.Southampton
Annie Prall 5 b. Southsea
1891 Southampton
William J. C. Prall 29 b.St. Helier, Jersey
Sarah A. Prall 25 b. Pertwood, Wilts.
Bessie E. Prall 6 b.Horsely Down, London
Willie C. Prall 5 ditto
(Willie Clark Prall birth was at St. Olave, Southwark)
1891 Southampton
John Prall 57 b. St. Helier, Jersey
Mary J. Prall 44 b. Southampton
1851 St. Helier, Jersey
Henry Prall 50 b. St. Helier, Jersey
Mary Prall 50 b. England
Ann Jane Prall 11 b. St. Helier
1841 St. Helier
Mary Prawl 35
Sarah Prawl 15
Cornelius Prawl 12
Mary Prawl 10
John Prawl 8
Ann Prawl 2
Hope this helps.
Annette