Chasing 392 to win, T&T were bundled out for 99 with Kyle Hope top-scoring with 26. In the second innings, it was Kevin Stoute and Kemar Roach who did most of the damage - sharing six wickets between them.
Alleyne's 186 in the second innings was his maiden first-class century and helped Barbados to a position from where they could not lose. His partnership of 216 runs with Shamarh Brooks (76) for the second wicket took Barbados to 317 before the declaration came in the 72nd over.
Hayden Walsh took 4 for 56 as Guyana declared their second innings after lunch on day 3 on 233 for 8.
Leeward Islands' chase started off well. Opener Kieran Powell - who top-scored with 79 in their first innings - stitched a 93-run partnership for the first wicket with Hodge before being dismissed early on the final day. Hodge then combined with Nkrumah Bonner (82) to add 155 runs for the fourth wicket to take the home side closer to victory. Both were dismissed in quick succession but by that time, Leeward Islands were 60 runs away from victory and Jahmar Hamilton (49*) saw them through to the win.
Shane Shillingford's five-for in the first innings, followed by Larry Edwards' 6 for 20 in their second put Windward Islands in a strong position as they bowled the hosts out for for 151 and 159. John Campbell top-scored with a crucial 67 in their second innings.
Jamaica needed just 27 overs to dismantle Windward Islands for 64. Damion Jacobs chipped in with 3 for 17 in eight overs.