Hi and welcome,
I actually put together some non-commercial flying tips;
http://flyingwithchildren1.blogspot.com
There is a section on bottle feeding on an airplane.
I recommend the bottles with disposable liners. I'm not sure if you can find them in HK but it's hard to believe anything isn't available there! (I used to live in North Point). That way, you don't have to clean whole bottles either on an airplane or in the hotel.
Please ask your doctor if it's really that necessary to sterlize bottles for a 3 month old. Most peds consider this to be an unnecessary task. If he says yes, for whatever reason, sterlization (sp?) tablets are definitely the way to go. All you need to do is ask the kitchen for a bowl and you're set to go.
Be sure that she's used a room-temperature bottle before leaving since warming them is also unnecessary health-wise.
It's actually a myth that babies have to suck on take-off and landing. She should be securely strapped into her car seat during those times. Your doctor probably told you not to feed unless she's in your arms. Even if you are saving money by putting her in your lap, please don't unnecessarily wake her to do this.
Before flying, schedule a well baby apt. and have the doctor check her ears and make sure she doesn't have any infection or blockage. Helathy ears can handle pressurization changes. The AAP recommends that babies simply be awake, not on landing but the initial descent, about an hour
before landing. As a Flight Attendant, I can confirm that is when people of any age would have ear issues. Offer a bottle if she'll take it but just moving her head, babbling, etc. will equalize the pressure. Take off is an easier adjustment.
Just let your baby sleep and feed as needed. I've never heard of getting a baby to sleep before a flight. I don't know how you'd keep her asleep during boarding! S'pore is a short flight for you so just play it by ear.
Have a good flight!