Final answer:
George Harrison wrote 'Taxman' for the Beatles' album 'Revolver', which was the follow-up to 'Rubber Soul'.
Step-by-step explanation:
The song written by George Harrison on the follow-up album for Rubber Soul, which is the album Revolver, is 'Taxman'. This track is known for its biting satire on the high levels of progressive tax taken by the British government, which was a major concern for the band members at the height of their fame. George Harrison's contribution to the Beatles' music expanded significantly in the later years of the band's existence, with 'Taxman' being one of his more memorable songs due to its sharp critique and catchy composition.