Hi there. Here is a list of what we usually tip when staying at AI's:
Baggage to room (at hotel, on arrival): $5
Transfer bus to and from Airport: $5 each way
Maid: $3-$5/day
Bartender: $5/day for day and $5/day for night
Breakfast and lunch buffets: $1/Dinner buffets: $2
A La Cartes: $5
We will also usually tip a pool cleaner/grounds maintenance/beach cleaner here and there. They are hard workers and almost always overlooked from what we see. I gave a pool kid $10 last year after I watched him clean the pool every morning and he was just beyond thrilled!!!
Generally we budget in about $200 for tips. They make so little and are so appreciative of anything they get to top up their wages. But everybody differs on tipping. Just wanted to let you know how we do it.
Have a great trip!