Released on parole. Byron and the other three were offered passage on a French ship bound for Spain. Three accepted the passage, with the other electing to take a mule across the Andes and return via Montevideo. The whole quartet eventually made their way back to Britain, where survivors of Bulkley's group joined them.
Byron's adventures along the way are recounted in The Narrative of the Honourable John Byron (1768), which also includes the story of his later circumnavigation and sold well enough to be reprinted several times.
During his absence, Byron had been promoted to Lieutenant, and immediately after his return he received a second promotion (to Commander), and on 30 December 1746 he was appointed to the 20-gun sixth rate frigate Syren.
After the treaty of Aix-la-Chapelle ended the War of the Austrian Succession in 1748, Byron commanded a succession of third and fourth-rate ships of the line and the guardship at Plymouth before taking part in Edward Hawke's aborted expedition against Rochefort in 1757.
After a further spell on blockade duty off the coast of France in the America, he commanded a squadron in Canadian waters during the Seven Years' War, supervised the demolition of Louisbourg's fortifications and defeated the French flotilla sent to relieve New France at the Battle of Restigouche. From there, he returned to England and continued in command of the Fame, mostly as part of the squadron before Brest.
So, at the end of the Seven Years' War, with a reasonably impressive string of achievements under his belt, Byron needed a peacetime role, right at the time when British interest in the Pacific was reviving.