This post, although being posted late, should be read before any other posts under References category. In a Vedic horoscope, planets are said to be in combination if:
These rules are numbered because the strength of effectiveness of the yoga reduces as we move from (1) to (4), which means that kshetra sambandha is the most potent and yuti sambandha has the least strength of all the yogas.
Further, location in houses 4th and 10th from each other are also considered as a combination from any of the planets. This is most evident in case of various Panch Mahapurusha yogas.
The combination of the planets should be seen in both rashi and chalit chart. If a planet moves in position between rashi and chalit chart, the combination would be rendered ineffective.
To explain (3), let us take an example of Venus in Pisces and Jupiter in Scorpio. In this case, Jupiter influences Venus through its 5th sign aspect, which means that we do not always need to look at 7th full drishti for this combination to be effective. The special full aspect of planets other than the usual 7th sign aspect are as follows:
Sun, Moon, Mercury and Venus do not have any other special aspect.