Bias depends on the plate voltage, you cannot just bias to a "ma" number without using the plate voltage to calculate the proper draw per tube.
You can use some of the bias calculators online to help you figure it out.
http://www.webervst.com/tubes1/calcbias.htmright at the top of that link there is a section where you select the tube type, put in the plate voltage and it will give you the draw in "ma". That is per tube so if you have more than one pair of output tubes you need to factor that into your final "ma" draw per side.
There are also some tables toward the bottom that will give you some baseline settings for cold, avg, or hot by tube type and plate voltage.