#1 IR increasing, so buy short duration bonds and sell long.
IR increases and so Bonds with long duration fall more. So you sell the long ones. You also buy Short duration bonds, so that your PF sensitivity to IR is lower.
#2 Yield spread is expected to narrow
Yield spread narrowing is good for the bond, so you go long on them. The way I remember is, spread getting narrower means your IR gets lower as well - so you go for longer duration bonds. You also go for lesser investment grade corporate bonds since, spreads across sector are decreasing.