I think the ban on Shanties on British ships (Royal Navy Only - never applied to the merchant fleet) stemmed from Napoleonic times. Prior to that they would have been allowed. The 'Bunch of Roses' or 'Bonny bunch of roses' is again, I believe, Napoleonic. Napoleon and his commanders refering to the Countries making up the UK as 'the bunch of roses'. Dunno why though - perhaps some 'in' French joke of the time???