The separation from Station Casinos, obviously, means that your Boarding Pass card and points will no longer be good at Aliante. If you have a Boarding Pass account, Aliante will match your tier status, but your points will begin at zero.
It makes sense that points for an individual property not match with a company that has multiple properties no matter how much goodwill it would have garnered with gamblers. In lieu of matching points, Aliante will offer "generous promotions and offers" to quickly reward customers for their loyalty.
Regardless of points, if you have upper tier status with Boarding Pass it might make sense to make the trip to Aliante to get an upgrade. There's usually benefits that go along with upper tier status that would make it worth a trip.