Speech and drama classes are not meant to improve a child's reading ability but more to encourage them to "open up", express more. Phonics classes may help to a certain extent but the effect will be too slow and ineffective, esp for a K1 or K2 child to prepare him to read in time for P1.
I am speaking from experience as my older child could read approx 800 words when he was 2 and now at age 5, is reading books meant for age 9 to 12. My younger is now 3 and is also reading simple books on his own.
I taught them to read with a trans-disciplinary thematic approach:
1. a combination of daily reading of good books (not readers)
2. reinforced with flash cards that are introduced together other thematic activities that I've prepared.
Through the above-mentioned approach and lapbooking which I do with my kids, they pick up an incredible number of new words every week. Because new words are introduced through the trans-disciplinary thematic approach, combined with lapbooking, the child recognises the words, learns the relevance in a fun and hands-on manner. Definitely more effective.
Sounds like a lot of work, but it is not. Anyway, I have shared a lot of our homeschooling approaches/ideas at my blog www.*******************************.blogspot.com