Answer: Not that I recall, but that doesn't mean it's never used.
Certainly, the forms of vayamos and vayámonos are the forms you would expect for the first-person plural imperative for ir and irse, respectively. After all, the standard rule is that the first-person plural imperative (usually translated to English as "let's" followed by the verb) is the same as the first-person plural subjunctive. In fact, some textbooks and grammar guides do list vayamos and vayámonos as the imperative forms.
But, for better or worse, you can't always trust the grammar books to know what is used in everyday life.
In everyday speech and even in writing, the shortened forms of vamos and vámonos are almost always used for the imperative. For all practical purposes, the shortened forms (vamos and vámonos) have become standard usage. The other forms are still used by some speakers, however; you're more likely to hear the imperative vayamos in actual usage than vayámonos. While the latter forms might be considered somewhat quaint, they would not be considered grammatically incorrect.
The vayamos form is somewhat more common when used with some set phrases, such as vayamos al grano ("let's get to the point") or vayamos al rescate ("let's go to the rescue"). Also, no vayamos may sometimes be used as the negative imperative instead of no vamos. In all these cases, however, you're perfectly safe using the vamos form.
You might also be interested in knowing that, at least in the spoken language, the use of vamos a followed by the infinitive is commonly used in expressing the imperative of other verbs. Thus vamos a salir is a common way to say "let's leave," although salgamos is also grammatically correct.
