I think there is a confusion regarding poly A tail.
Poly A tail is a post transcriptional modification of mRNA in eukaryotic cells. Most of the eukaryotic expression vectors have a sequence required for Poly A addition by poly A polymerase.
The another "A" tail is used for cloning PCR products using T/A cloning. Here single adenine is added to 3' of the PCR product by Taq polymerase.
Coming to the specific question,
pRSET B is a E coli expression vector and adding polyA tail doesn't arise.
I my understanding is right, the question is regarding addition of 'A tail' to the 3' end of PCR product. When you are using RE sires for cloning you need not worry about addition/removal of A tails at 3'end of PCR product.