I can't get the picture to open up bigger but to me they just look like a plain round tip
I agree, you can use a round tip and flatten it your finger a bit.
Yeah, I would definitely say just a round tip. Did you learn how to make hearts, carrots, etc...? like they do in Wilton course I or II... I can't remember It looks like the same method. I think you would just hold your bag upright, squeeze and move slowly, releasing pressure to make the point.
definitely a round tip (or series of round tips if you include the detail in the centers of the flowers). for the flower petals, try sizes 4 through 7 to practice to see which one gives you the shape and control you'll need to pipe. basically, it looks like a series of tear-drop shapes piped so that their tails connect in the center, and then the centers piped over in dots in contrasting colours to cover where the petals meet and to add detail. the ones without centres look like just pearl and teardrop shapes piped close together and overlaping to create the 3-d effect of flowers seen from the side. grab the deepest cake pan you've got, invert it, and use it to practice piping these shapes onto a vertical surface as you ultimately will be doing on the sides of the actual cake.
It looks like the flowers are used with tip #3 and the vines are a tip#1 or #2. Very pretty cake!