In English, any noun can be employed as if it were a verb. Don't let the grammarians tell you otherwise. Using the noun "text" as a verb is a case in point. This usage was introduced into the language by young people. Young people were the first to assimilate the smartphone into their culture.
In Spanish, the form of a word indicates the part of speech. Hence texto and textear are two different words. (Of course, yo texto is a verb form that coincides with the noun form). Any new word encounters some resistance by the folks who uphold the current standards. That resistance is more formal in Spanish culture than in English culture.
Hence, you're going to get plenty of answers that tell you not to employ such a verb until after it has been accepted by the RAE. That's not how it happens in the real world. The future always arrives too soon, and in the wrong order.
To get back to your question, the use of an indirect object for the recipient of a text message will depend on the speech patterns of the early adopters. The chances are they will mimic the pattern established for some other verb that means comunicar is some special context. I chose the verb telegrafiar for lack of a better alternative.
See definition
If this is any guide, the target of the communication will take an indirect object. However, you should read up on the link to laismo/leismo that Diego provided.