Pulmonary interstitial oncotic pressure actually decreases, b/c increased capillary filtration washes out interstitial proteins, reducing protein concentration. The same reason for why you have increased capillary oncotic pressure at the beginning of renal efferent arteriole.
thinkenergy is right. When you have transudation, there is washout of proteins, which dilutes the proteins and decreases the oncotic pressure in the interstitium. Phloston is wrong.