You can't use the railways to Newbury until 1847, the GWR completed the line to Bristol in 1841 but avoided Newbury - earning it the alternative name of the Great Way Round, but making towns out of Didcot and Swindon.
The Castle was already in trouble in the 1830s, so the Pelican would be the obvious place to stay - he might even meet Dickens in the dining room. Dickens described the Pelican both before and after the railway - in stark contrast. In a letter to his editor in 1835 he praised the inn and its accomodation, whereas in the Uncommercial Traveller (pub 1845 - Chap 24) he describes an inn (the Dolphin's Head) in terminal decline that is believed to be based on the Pelican.
In the 1830s the landlady of the Pelican was the redoubtable Mrs Botham - Frank Stillman in his booklet on Victorian Newbury (1893) described the Pelican and Mrs B:
Famous amongst these was, of course, the “Pelican,” of which Quin, the actor, wrote the oft quoted lines—
“The famous inn at Speenhamland,
That stands below the hill;
May well be called ‘The Pelican,’
From its enormous bill.”
Whether this was “writ sarcastik” is not related, but the landlady, Mrs. Botham, was a popular character with all travellers along the road. She was genial, jolly, and business-like, and presented a pleasant picture, as with rotund form, ruddy face, lace cap and black silk gown of irreproachable quality, she stood at the door, smiling and bowing as her distinguished patrons drove off. Or what more comfortable prospect could await the weary traveller, who in those days truly found his “warmest welcome at an inn.” The “Pelican” then was a big establishment, occupying a much larger area than now, the frontage extending from Messrs. Hunt’s premises right down to the “Cross Keys,” the establishment also branching out into the backway of Speenhamland. There was accommodation for a small army of travellers, but even then the resources of the hotel were sometimes severely taxed. There was a long range of stabling, and frequently as many as 300 horses were put up there. A corresponding number of grooms and ostlers, found employment there, and only the older generation who were acquainted with this particular class of men can fully appreciate the humours of the Wellers, father and son, so admirably portrayed by Dickens. Old Harry Scroggins, who eked out his later years by selling nuts and oranges, was almost the last of the post-boys, who attired in yellow jacket and white breeches, were as familiar as the old yellow-bodied “shay” peculiar to the “Pelican.”
The railway did for Eleanor Botham, she was declared bankupt in 1841 (the railway had bypassed Newbury the previous year when it ran a service from London to Wootton Bassett near Swindon). Mrs B was left with a large coaching business - there is evidence that her husband George her predecessor as licensee owned more than 100 horses that he hired out to travellers needing a new team to take them to Reading or Marlborough. The Pelican kept going for a while longer and the yard supported a livery business into the C20th but the glory days ended in 1840.