Aruba is in region 1, right? So you should be able to upgrade any fare, even the Travelocity bulk fares. I've bought a Travelocity package to Hawaii which included UA flights (booked into T class) and they were upgradable.

If you're nervous, call Travelocity and ask what booking class they use, then call UA and double check. For flights within Region 1, I'm 99.9% sure you'll be able to upgrade.

Flights to Europe, Asia, etc., are another matter. Packages there are unlikely to book into an upgradable booking class.