Is this the correct way to wire my transformer?
A few thoughts come to mind:


15v secondary implies ~21v peak. So the differential across your regulator will be 9 volts. Quite large. If you are intending to use 30va at 12v, this implies 2.5Amp max. Which means 2.5 x 9 = 22 watts in your regulator. But with max &lt; 1amp (based on your fuse) this is lower, but still high. 


However if it's a inductive buck regulator, then less of an issue. 


Center-tap transformer does not require  a bridge rectifier. Only 2 diodes. Look it up. 


[CORRECTION] For a dual supply you WOULD need 2 bridges. 

Otherwise seems ok.