You should call someon after the first date. It is more polite and more formal. If you text them then the meaning of what you have to say may be lost. After one date you typically don't know the person well enough to understand full message through text so calling is much better if you want the relationship to last.
After a first date, I think calling is the best decision. Calling is more personal then texting that the world we live in today so heavily relies on. Calling is the closest thing to face to face talking, so after a first date, calling is definitely better over sending a boring text.
Texting is something that should be used sparingly to begin with. In most circumstances, here is no reason to be jamming on a bunch of keys when you can hit a few, call someone, and have an entire conversation.
In a situation such as this, it is certainly inappropriate to text the other person. It's not personable at all and comes off wrong. Just call them like any sensible person would do.
I would always call, for two reasons, 1: Verbal communication is more personal and you can gauge their enthusiasm and how much they think of you by vocal queues like the tone of their voice. You cannot get such queues from text messages as easily.
2: I have a sexy telephone voice as I have had women calling me, just because they like hearing my voice. Though I did once consider starting my own sex line, but, I'm the same, I used to ring orders through to one of my part suppliers, instead of emailing, because I like their receptionist's incredibly sexy, husky voice. It was like having Stevie Nicks on the other end of the line, LOL.
Though, if I was extremely bad with words, had a rotten phone voice or stuttered,badly I would probably choose to text instead.