When marking a spelling test, how would you mark words in which students who may have misspelled a word, however, they have demonstrated their understanding of the focus phoneme/grapheme. For example: ‘dolphen’. The focus is ‘ph’ as f, however the student has used e instead of i? Is the incorrect spelling correct or incorrect?

Words are either spelled correctly or incorrectly. There really isn’t grey area.
If a child attempts the word ‘toast’ but spells it as tosttoat, toastoats or oast…  all of these are attempts are incorrect and would be scored incorrect in the PLD Placement Test, but also in tests such as the South Australian Spelling Test.
In some of the examples listed the application of the key phonic concept (e.g. óa’) was correct but the other letters were incorrect within the word. To spell a word correctly students must apply the essential pattern along with the other components within the word as a whole.
Teacher judgement always comes into the process. Some students you can determine their levels on the basis of their percentage scores. But for others, teachers may say because they are borderline students (and almost at the required 85%) that teacher judgement prevails. Sometimes teachers will decide that students need to be held back to further consolidate their skills and for other students that they should progress on to the next level.
In every class, when marking spelling tests, there are students that are straight forward and clear to mark, assess and plan for. There are also typically a small group of students that are not straight forward for whom teacher judgement prevails.