Well..
Dthrow chain: when i have done this (i might have messed up but) bowser is able to get out with Bup, but you can bite them if they try to do that. This is kinda weird. when i dthrew and bite but the bowser didnt do anything at all my bite missed, BUT if the bowser did anything at all when my bite was out my bite ate him, including shield.
Fair Dair nair are all good.
Up air juggles good. If they airdodge i dont think they have anything fast enough to hit you so just dair or something.
Grab release: Wario air breaks.
fsmash, up smash, up tilt, ftilt (tilted up) fair, bair, nair, dair, Bup, CLAWWW
dont get grabbed: besides from the obvious grab release, bowser can regrab you many many times for easy damage.
This matchup is in our favor but bowser shouldnt be taken lightly. Bowser can kill easy and if you fall behind and start charging you are in trouble bowser does like 15 damage per hit. and kills easily with one grab > up smash at like 90
Ban: halaberd, FD
Counter: Rainbow, frigate (take advantage of the right side of the flat part) nothing else really comes to mind for a great advantage.
Overall: 60:40.... an average wario has a solid chance against ANY bowser.
DONT GET GRABBED BOWSER CAN TECHNICALLY 0-DEATH YOU!!!!!