Let's talk Anglo-Saxon (Projoy) I think you can run over the barlines, as you say, if the two words are part of a phrase but I think it would be stretching the definition to breaking point to call that first line 3 amphibrachs. One possibly i.e. "amphibrach" but I'm not sure where the stress lies. It's not in my Concise Oxford Dictionary 1964. Too bloody concise, obviously. :-)