Both nice places to visit, but I wouldn't call either a day-trip.
Why would you not call either a day trip? They are both about 2 hours drive from the capital and easy day trips I used to constantly enjoy when living in SD.
Also, it depends on what you want but La Toma de San Cristobal is not what I consider a nice getaway. There's scores of people packed in the pool, drinking with booming reggaeton, merengue and bachata. Given, someone might enjoy that but not me, personally.
A day trip to Jarabacoa is great. Once you arrive in town, take a hike to el Salto del Jimenoa along the Jarabacoa - Constanza highway. Then get some lunch, take a swim in La Confluencia or even visit Monte Alto Coffee. In the afternoon, take a short hike to see el Salto Baiguate.
If going to Samana, don't forget to make a stop at el Salto de Socoa along the Samana highway. It is a beautiful hidden waterfall just off the road. When you get to Samana town, you can take a boat out to Cayo Levantado. If not Samana, head up to Las Terrenas and hike to el Salto de Limon.
You'll need to get up earlier for Samana but it's doable. Jarabacoa is no problem.