This is what @blocktrades was referring to in an earlier reply.

When we create an account we actually give you your 3 Steem back as Steem Power rather than as a delegation. This never expires, and you can build your account on this foundation.

With a free account you get a delegation, which has a finite life span, and although it gives you earlier access to more SP you will need to plan for it's expiration.

So, to directly answer your question, no: a purchased account through BlockTrades does not come with a delegation.