If I see another members post or review and I wish to send a pm, is there a way  to tell whether that person has VIP membership or not?

The best you can do is PM them and see if they respond.

Now if they have a review which has posted within a few days, they probably have VIP as TER awards VIP days as follows.

1st Review - 0 days

2nd Review - 30 days

3rd Review and after - 15 days

...if you click on the name and a box will pop up to compose a PM if they are VIP.

If a box does not pop up, they are not VIP, so if you send one on your own, they will not get it.

it means they are VIP and use alias

You also need to be clicking on a name with an envelope next to the name....you can't PM an alias.

Basic members have boxes displayed but they can not read any mail they might get.

if you are basic,  no PM......if you click on a name with an envelope and no PM box pops up, they are basic, can't write an e-mail if they can't receive it anyways.....if it pops up, VIP.  Can't PM an alias.

You can send private mail to basic members. They just can't read it. And there is no way of knowing is someone is basic or VIP. If they answer your PM then obviously they have VIP.  If they don't answer, it could be that they have basic membership and never got the PM, or they are VIP but ignoring you.
Not sure where you got your infomation but the PM box will open for basic and vip, and allow you to type a message and send it. The problem is the basic member can not open it, and you have no way of knowing if they are a basic member and never got your message.