If I fly syd - dxb, and my interlining partner is based in Holland, and he flies ams - dxb. Will the interlining be affected or is it only at your hub airport. Will passengers fly Syd - dxb - ams - lhr?

Or is it not worth the cost of the Ils?

Yes you may have passengers flying from SYD-DXB-AMS-??? as a AS passenger will take upto 3 flights to get somewhere. As long as the flight times allow enough time for a connection then they will transfer