You enable text bullets (I used Bullet Big*). By default, a bullet will appear in the Bullet: window. Back-space this bullet, and replace with [1.], and press return. For my example, I set the text indent to 0.5 in. Copy/paste your first content into the first bullet text location. Now, copy/paste the second bullet content immediately following the period of the first bullet text.
Set your After Paragraph setting to 9 pt for this example. Now position your cursor between the first bullet content, and what is expected to be the second bullet content — and press return. The [1.] is repeated and its content is now wrapped. Back to the bullet section of the Format Text panel. Just change the number inside the brackets, and press return. You now have two, number bracket list items. Continue to follow this pattern to build your bracketed list items.
If you had attempted to paste the content for the second item after you had pressed return from the first, the content would have overwritten the second [1] — before you could change it.
The following will export correctly to PDF, and opens correctly in Word 15.10 in Office for Mac 2016 Preview. The brackets are lost in LibreOffice Writer v4.4.3. The formatting (Word) is retained by Preview on Mavericks, but Preview on Yosemite destroys the "0" second indent (default) on Mavericks, and line wrap is lost. The .docx formatting is retained by Pages v5.5.3 on Yosemite.
Result from Pages v5.2.2.