Had the same problem and answer bellow helped me to see the subtitles on TV screen. The only limitation I currently see is that the internal player control the size of font on the phone screen but not change it externally. In addition, the subtitles position in both screens are slightly different, which point on different processing for internal and external view.
In addition I had a problem that the Hebrew subtitles does not shown but I saw question marks.
After some investigation and tests I found that the internal player on my Galaxy 2 accept only unicode srt files, designed for RTL read. Since most of the subtitles in Hebrew are historically published as ANSI and LTR read (since the DVD appliance days that were limited to this format. Currently most software and streamers read all formats) I had to convert it twice:
1) Open the ANSI file in Subtitles Workshop and fix punctuation (Subtitles Workshop works only with ANSI files).
2) Convert the file to Unicode (using Notepad "save as" command and choosing Unicode or UTF-8 format).
BTW, usually I use mVideoPlayer. It requires RTL file so I had to do the first step any way before transferring the movie to the phone, but then it doesn't support the Unicode file that I saved. After more test I found that it plays UTF-8 files. Since the internal player is luckily support both Unicode and UTF-8 formats, I can keep only one file in UTF-8 format and RTL direction of punctuation.
The only problem is that Subtitles Workshop doesn't support not Unicode neither UTF-8, so if the srt file is originally in these format, I can't fix the punctuation direction (I didn't find another tool) unless I lose the special characters like notes you can find mainly in musical.
Hope this helps for other users, specially for RTL language users (Hebrew/Arabic).