Well, Wolfram|Alpha is not Mathematica and in general, Mathematica syntax does not work with it. W|A has a natural language interface, which makes it possible to ask questions without learning a programming language. But it can also be very frustrating to get it to do what you want (at least I find it very frustrating and unpredictable).
Try telling it to
select primes from {1, 2, 6, 15, 37, 90, 218, 527, 1273, 3074}
Based on the interpretation of this natural language query above, I tried
Select[{1, 2, 6, 15, 37, 90, 218, 527, 1273, 3074}, PrimeQ[#1]&]
which also works.