(1)∵a2=a1q=4,a5=a1q4=32联立方程求得q=2,a1=2
∴an=2•2(n-1)=2n
(2)bn=log2an=log22n=n
∴数列{bn}是以1为首项,1为公差的等差数列
∴Tn=
n(n+1)
2