Benefits:
1. Airfare reimburse upon the completion of the contract -> they say "Reimbursement" but read the contract, sometimes its only a set amount paid out at the end of the contract. This is somewhat negotiable and roughly speaking goes along these lines: 6 month contract (1 way ticket); 12 month contract (round trip ticket)... 
2. Medical insurance -> If this is REAL health insurance, this is a big perk. But what does it cover? Does it cover western hospitals and medication?
3. Rent-free furnished apartment -> Another incentive that needs to be investigated. We lived in sub-standard dorm rooms (with kitchens) way outside downtown. Before signing any contract  make sure to investigate and see pictures of WHERE the apt is located and what type of condition it is in. GET PICTURES!
4. Holidays -> standard, and should be paid
5. RMB 2200 per year travel allowance -> Is this seperate from airfare reimbursement? If so, nice bonus.

A few other things to keep in mind:

• 20 teaching hrs a week does not mean 20 working hrs a week. Schools often have you work 4 hrs a day, but not consecutive; instead, you work 2 hrs in the morning, 2 at noon, 2 more at 5, then 2 at night... long story short, you may think your taking a part-time job, but you will be working full-time.
• Get everything in writing!... IE all the perks.  Many companies tell you everything you want to hear. Such as: "We have weekly Chinese lessons", "we provide you with curriculums", "we....". Anything that entices you to take a job, make sure you include on the contract or have written somewhere. Because, as soon as you sign the conctract, that is the only thing that matters and is a HUGE bargining chip. 

It has been recommended to look at seriousteachers.com to find a viable school or program tat might interest you.