I would say also this depends on what app you are using. For example if using Crestron Mobile Pro G then it simply 'stretches' and 'squashes' the page to fit landscape, you then have the option to anchor buttons and sub pages to various areas of the page when it rotates to keep the position. My suggestion here is, for example for network logos to use a square subpage which is the width of the portait page and keep the aspect ratio - you lose the use of the width in landscape but the buttons will stay in position.
However if you are using CommandFusion iViewer it will use 2 different pages for each orientation, therefore you can spread out the icons to where you want them for the landscape version. I reckon if they are the same icons and are in a similar location on the page it will be pretty clear that you are just looking at a landscape version of the portrait page (if that makes sense).
If you want to be more technical about it you could do a little maths - for example if your icon is at X=100 y=200 in portrait then the coordinates for landscape will be x = (1024/768) x 100 = 133.333 (round down to 133) and y = (768/1024) x 200 = 150. So x=133, y =150.
Piut more simply - multiply the x coord by 4/3 and the y coord by 3/4.