Two opposite ends of the gravity range.I got to do one of those. It sounds really, really good. Honestly, for someone who has been brewing for a long time, I don't technically know what a barley wine is...or an English bitter.
Bitter is 1.040ish amber beer of British origin owing to wartime material shortages. Hopped with British hops, usually Kent Golding or Fuggle or similar. Maris Otter malt and some crystal malt at its simplest, can include things like biscuit malt. British ale yeast. We can usually find Boddingtons here in a nitro can. Otherwise not too well known here in the US.
Barleywine is a strong beer all about excess. American versions are usually in excess of 1.100 starting gravity and hopped with a whole bunch of high alpha American hops, American ale yeast. 12%ish. British versions are usually not as strong, 9-10%ish, British hops, British yeast. American examples are things like Sierra Nevada Bigfoot or we can usually find Wyerbacher Blithering Idiot here. Britsh Versions are things like Youngs Old Nick (not sure if they still make that) or Fuller’s Golden Pride.