No. The contact form and the booking form is not part of the same process, meaning it's OK to have the button placement differently. The contact form is usually a simple form with limited number of fields to enter, such as Name, Email, Phone and a Text field + the button. The button is often left aligned with the message textbox as seen below. There are variations where the send-button is right-aligned with the message textbox - but, as you say, the vertical alignment with the text is lost.
The booking can be a rather complicated process, with multiple steps such as a wizard. Then it's often the other way around where you right-align the button to give a feeling of turning a page in a book. Thus the buttons in a multi-page form is right-aligned (Note: there are variations here too).
Beware of cultural differences though. Some countries read books right to left where the book-analogy wouldn't work. As always it's recommended to study your target audience use on existing web sites before going into production.