VT is quite good as representing the world weighted. However, China is under represented because VT doesn’t include all China stock for exemple China A share. Have a look at http://www.ftse.com/products/downloads/About_FTSE_China_Indices.pdf
Personally, I have bought some shares of Lyxor MSCI China A Fortune SG (DR) UCITS ETF (FR0011720911) to mitigate this issue. This fund is very illiquid, however it tracks the index: MSCI China A and not the MSCI China A international tracked by other providers.