I finish a bow with a few coats of Danish oil which is a wipe on finish. After that I use a beeswax based polish, Lord Sheraton's Furniture Balm. They have it is Sainbury, it's the more yellow of the two Lord Sheraton products.
This finish is a light sheen, not a high gloss. IMO anyone who likes a high gloss on a longbow should be horse whipped until they desist....
(The reason being that modern high gloss polyurethane finishes are a pig to remove if repairs/modifications are needed. Oh and they look horrid...)