"Blue line" is just another name for blueprints. Redlines are markups of the original plans...essentially an "as built" as civilman72 noted.
A corrected bond is a close-out document whereby the actual bond amount (the performance bond and/or payment bond) is reflective of the construction. As an example, suppose a payment bond was initially set to cover all subcontracts, but during the course of construction, the total construction cost increased by 10 percent. Then the payment bond should be increased by 10 percent to reflect the new cost. It becomes moot after all payments to subcontractors have been made and liens released, but in the interim, the bond should reflect the costs. The same is true of a performance bond....if the cost of construction increases, so should the bond.