To avoid confusion, extra points for a visa application are achieved solely from your exam scores, irrespective of which exam you choose to sit.
In IELTS: the most common method is to achieve Band 8 scores in all 4 sections of the General IELTS exam, Listening, Reading, Writing and Speaking.
As IELTS scoring is not a %, out of 100%, Band 8 in General IELTS is achieved by the converting your score. For example, in Listening 35/40, Reading 37/40. The lower score in the listening section is because this paper is combination of both academic and general content. Writing and speaking are marked in a more complicated way and so while your IELTS Speaking score should always be Band 8, and above, for native-English speakers, IELTS Writing Band 8 is tricky!
In PTE: this is is an academic exam, designed as listening and note-taking exam and therefore completely different from General IELTS in respect of the tasks you are asked to complete. Although, essay writing is similar in both exams, and marked on the same criteria. Therefore, the aim in PTE is to score 79+ in all of the top 4 scores, Listening, Reading, Speaking, Writing.
So, the best advice I can give is to research both exams, before you choose, rather than only looking at computer delivered, PTE, versus paper-based, IELTS.