At this point of their development, Taillon looks like he's at least a full year ahead of Allie.
I'd look for Allie to spend the entire season with State College with an outside shot at jumping to High A West Virginia. Taillon has a chance to make a late season jump to AA.
Nothing but speculation on my part but you'll also see it linked with him in prospect scouting reports as well but it shouldn't be a surprise if Allie ends up as a closer down the road.
Don't look for the Pirates to be in a rush to sign Gerrit Cole in order to get him into their farm system this summer. He's thrown 114 innings so far this year and they will be content to get him signed before the August deadline and best case, possibly have him pick up 30-40 innings in AZ fall ball.
At some point next year, Cole and Taillon should both be at AA Altoona and I'd be tempted to make the 2 hr drive up to see either pitch.