Is there any way to separate this short code into its own function? (webserver, trying to use client.print outside of main loop)
You can pass client to the function by reference, like this:

void displayBullet(EthernetClient &amp; client, int toggle) 
  {
  if (toggle == 0)     //switch is off, so display red bullet
    client.print(F("&lt;font color=\"red\"&gt;&amp;#8226;&lt;/font&gt;"));
  else    //switch is on, so display green bullet
    client.print(F("&lt;font color=\"green\"&gt;&amp;#8226;&lt;/font&gt;"));
  }


Now it knows about client. Make sure you pass client when you call it:

displayBullet(client, 1);